Porting 317 heads 898 Bore GM Reman 6. so I called up my machine shop to ask about getting some valve/porting done to either my heads or some 243's while they were off. The 317 is better in port design, valve area, port energy and efficiency. Jan 23, 2017 · Treated to their Stage 2 porting, peak flow numbers for the 317 heads increased by more than 70 cfm, with substantial gains through the entire lift range. Jan 17, 2012 · My question is about the cylinder heads since I want to be around 10. Brian Tooley is about the only one that comes to my mind. You would see a dramatic drop in compression and you'd end up losing power. 0L Truck Castings Jun 20, 2023 · The following are permitted: cylinder head studs, polylocks, jam nuts, screw-in or pinned studs. 8 liter twin turbo setup in my 1983 ltd sleeper wagon build they have a Jun 6, 2018 · The best factory cathedral port heads (243, 799, and 317 castings) flowed near 250 cfm, which represented a huge step up from the conventional small-block heads that preceded them. Armed with the right knowledge, the correct tools, and a couple of nights i have a set of 317 heads and an lq4 block when i build the 408 can i run the 317 heads and flat-toped pistons to keep my compression at around 10. Jun 22, 2021 · The most popular upgrade is to replace the stock 317 cathedral-port heads on a 6. 0-liter Feb 13, 2020 · Dyno testing on an LM7 5. WHICH HEADMAKES MORE? We compared the four most popular stock LS heads in a back to back shootout. 19:1 compression? Actually the 317 heads on a stock bore/stock stroke LQ 6. 19 x 0. 706 Heads vs 317 Heads. An As Cast head that is just as efficient as competition’s CNC ported pieces. Jun 11, 2018 · The best factory cathedral port heads (243, 799, and 317 castings) flowed near 250 cfm, which represented a huge step up from the conventional small-block heads that preceded them. However, the Dec 31, 2016 · I've been around two sets of 317 heads that were 'home ported' on boosted 6. Jul 24, 2024 · The 6. Any valve job accepted. I wish you the best with the porting! I have the low compression 317 heads on my 6. 88 stainless (back-cut and swirl polished) valve combo, 122cc combustion chambers, and intake flow that exceeded 400 cfm These BB-Chevy heads come in an As-Cast series or Full CNC-Ported series. CNC Ported Cylinder Heads. LS/LT1 Series Heads. 3, or 5. Truly not worth the effort. 149 x 1. Easy fix there should you desire it. 55 inches Compare to the normal 6. Jul 21, 2023 · The cost of porting a cylinder head typically varies depending on factors such as the cylinder head type, the level of porting needed, the geographical location, and the level of expertise needed. Milling down the 317 heads is possible, but expensive to do. It performs on par with most aftermarket heads. 0. 6rrs and all the supporting mods. 660" Spring Kit and Titanium Retainers $ 1,999. 3 Gen IV Aluminum Block 5. 7 blocks), but the results are impressive. You are almost in reach of the L92's. Hoping to run high 6's/high 10s N/A on pump gas. Many would say Parts - Cylinder Head Parts & Services - GM Katech CNC Porting LS2/LS6/Truck 243, 799, 317, 035 Cylinder Heads (PAIR) In Stock (0) Reviews: Write first review. 00-1. 0. 267cc-280cc Full CNC Porting Package Our Full CNC porting for GM 823 L92's is a great budget head for 600hp+ builds. Compare to any brand, this head makes power! Mar 13, 2018 · 706 vs. Feb 28, 2013 · Porting cylinder heads has long been a right of passage for serious hot rodders looking to add power on a modest budget. 898" Floated Pin Flat Top Pistons 3. Includes the bowls, port match, and profiling of the combustion chambers. Chevrolet LS Aluminum Head, 317 Casting. Sep 2, 2015 · Advanced Search Cancel Create thread New Forums More Login / Join Nov 24, 2021 · This compression loss ends up being a net horsepower loss for 317 heads, even with their superior ports. We’ll run through each iteration below, providing chamber and valve sizing, and their pros and cons to help you decide the best LS heads for your build. This doesn't include intake gaskets, valve cover gaskets, coolant, etc. Was wondering what kind of power it should make with untouched LS3s and with the right camshaft of course. Personally I would think the smaller chamber 243 head may not be the best bet if you plan a lot (say over 5-6 PSI) of boost pressure. 945 Pin GM Nodular Reman Crankshaft 3. Independent flow bench testing shows over 400 cfm with 2. 650 . Well before I got a chance to get the car to the track I blew a few pistons and rebuilt the motor with stock pistons but 317 heads in effort to lessen the horsepower some. 0 especially if you plan to go the boasted route. it'll be fine Alright everyon Sep 29, 2008 · Dart 225 heads fully worked by PMFL, FTI StreetSweeper cam 236/240 . Attn: Cylinder Jun 2, 2016 · this is a video of how I ported my 317 casting number heads that I am putting on my 4. I'm working with 317 heads that come on a 6. proheads. 700 lift. o CNC Porting – Occasionally a 100% CNC ported head might have a very small area left “as cast”, this in no way affects performance. Complete CNC machining of your supplied cathedral-port cylinder heads, milled to your desired specs, assembled, and pressure-tested; Choice of TSP camshaft; TSP Hardened Pushrods ; The price listed is with the customer sending us his/her cathedral-port castings to upgrade for porting, valve job, and milling. 3l? should i swap to 317 heads on my 4. 242. 89 inches Exhaust Valve Diameter: 1. The air speed is insane on these. All out of a 317 head. 0L, the 706 heads have gained a reputation for their versatility and performance potential. Shop Now at the Guaranteed Lowest Price! $5 off $49 / $15 off $249 / $30 off $499 / $65 off $999* - Use Promo Code: SPEED Jun 12, 2023 · Based on head flow, standard LS 243 heads may generate about 5% more power level than factory LS1 heads. I would just spend the money towards the fuel side and get some AFR's or Trick Flow's down the road vs. These heads have larger port and valve sizes, as well as different intake runner shapes, such as rectangular ports . The large valves in the LS3 heads require the 4. OEM and Aftermarket heads enter FED’s advanced manufacturing processes proven to generate the most efficient power in every application. haha my goal is a cc503 cam, 1. 600 . 57 valves and valve job technology developed and used in the TrickFlow 215cc head this head has awesome mid-lift airflow. With all PRC cylinder heads, quality and performance are our two highest priorities! Apr 29, 2018 · Im just going to post how a basic 317 ls head can be ported in different stages. 591 114 Old heads: LS1 LS3 11 Degree LS7 LSA 243 799 862 706 317 CNC ported Shaft Rocker Arms. Inventory 11875 5. CNC Ported Heads. The same goes for swapping the heads to aftermarket castings - since I'm not building a forged bottom end for this truck (someday I may throw ARP rod bolts in it), that's a huge waste of cash. 0L 317s. 500 - 317 cfm / CNC Ported 338 cfm. 0 heads below Casting Number 317 Head: 2001+ LQ4 6. 300 valves. o Valve Spring Installed Heights – FED valve spring installed height spec is +/- . 965, while the "243" unit was 3. Sep 24, 2015 · Cathedral port cylinder heads have been mistakenly dismissed by many in LS-series circles for being “old-tech. 3 with 706 heads hp shows that the ported 706 heads hp gain or improve its power output by 20 hp and 15 lb-ft over the 317 ones, though the latter has larger valves than the former. 5:1? 2) Or do I mill the heads to bring up compression and size the pistons accordingly? 11. 610˝ exhaust valves. On the contrary, some cylinder heads boost the engine’s performance due to their unique architecture and design. Though the 706 heads have smaller Feb 15, 2017 · I am not porting the heads or altering the combustion chambers, research has made me decide it is not worth the $$$ for my intentions of a final result. 5:1 compression. 8l, 5. Their cathedral port design is known for efficient airflow and good velocity, making them a versatile option for naturally aspirated and boosted applications. All flow numbers for For Hemis Only Ported heads come from their Web Site updated March '13. However, porting is expensive; therefore, casting 706 heads in stock form is the best option. However, the Get the Best Performance with ProMaxx Performance 317 Series Aluminum Cylinder Heads Big Block Chevy 9317 parts at JEGS. Mods: 4" mafless cai, ported TB, ported L76 intake, Yella Terra 1. For a street car, this design means excellent throttle response, torque and average power. Jul 25, 2013 · Re: LS6/LQ4 317 head porting questions Post by jason snyder » Fri Jul 26, 2013 5:03 am Work the intake side as much as possible , remove the rocker boss ( PITA) , And remove the ramp at the guide boss , use larger valves , and transition the bowl for the larger valve . Jul 16, 2007 · 6. 0 LS could be had with one of six cylinder heads: 317 heads, 243 heads, 799 heads, 821 heads, 823 heads, or 364 heads. RPO LS7 cylinder heads are 356-T6 aluminum with 70cc CNC ported combustion chambers, raised square port, CNC ported intake ports with 259cc runners, D-port, CNC ported exhaust with 86cc runners, 2. Sep 22, 2014 · I currently have a set of ported 317's on a 408" lq with a billet 88. 00) Brodix bb3 xtra 345 package cylinder heads with cnc chambers, . Porting cathedral port LS heads!chamber softeningpolish chambersremoving swirl rampscutting rocker boss downfirst timer eh . 0 bottom end will give up the ghost before those heads slow you down if you're willing to add boost and meth. 610 . 7L 3. 00) Thompson motorsports cnc ported 317 heads pac racing 1218 springs . 6 Exhaust Valve, 4. Jul 26, 2016 · Where the stock 243 heads featured 65cc chambers, the 317 heads featured 72 cc chambers. The 317s were given the nod over the 243 since they offered the larger chambers that most closely duplicated those on the LS3 (71cc). 08 versus 2. 600 and 450 cfm at . 622" 58X Reluctor King Main/Rod Bearings Frankenstein Ported 317 Heads (Cathedral Port) Cam Motion 226/2 Jul 3, 2023 · The name “706” comes from the casting number associated with these heads. Does anyone have any other suggestions on who is good? FED specializes in high performance cylinder head porting for racing engine applications. Factory castings are capable of 360 to 400 cfm when ported properly, which can make it difficult to justify an aftermarket casting. 015” which is the smallest shim available for adjustment. 00) Nov 17, 2006 · Yes the 317 heads flow better but would be a bad idea in a naturally aspirated application due to their 72 cc combustion chambers. 06cc Compression Ratio: 10:1 Intake Port Volume: 210cc Exhaust Port Volume: 75cc Jun 13, 2023 · In reality, the Dyno tuning or Dyno testing of 5. If you sell those and take the $400 head port money. from what ive read this setup on stock heads (not ported) put about 360-370 rwhp with a intake and full exhaust. 581/. 3L HEADS vs 241, 799/243 vs 317s. I was anticipating some 10. Jun 30, 2019 · May want to read through here on the OEM head, just for some reference on the 243 vs. 04 and 1. CNC ported GM 317 Castings. Stage IV: $1000 Our "hot rod" port job- for nitrous and forced induction applications. 317 heads on any short block larger than 6. 1-7/8 longtubes, yada yada. That, and a bit more costly. Your goal is low speed and midrange torque. 10) and port volumes Oct 7, 2013 · im slowly piecing together my cam/supporting mod project. 1) Do I port,polish, and give them a 5 angle valve job and size the piston to bring up the compression to 10. 3 Gen IV Aluminum Block 346ci - 545hp Long Block 5. 3L. Just get them milled a little to up the compression and get a multi-angle valve job. Feb 2, 2014 · I would not bother porting some 317's. Dec 1, 2010 · 317 . Nov 7, 2021 · General Q & A - Promaxx heads and Valako - Jim has done an awesome job on my heads. The biggest difference between the 317 cathedral-port heads and the LS3 heads was the port shape and attending flow rates. We ran the 706/862 Jan 27, 2014 · Ported 317 heads and a billet S476~S480 on a T4 should have no problem getting into the low 9's high 8's on a decent combo@37~3800 lbs. A set of ported 317's I think would be a better choice for me. 0 Litre Truck Material: Aluminimum Combustion Chamber Volume: 71. Dec 22, 2017 · Having tested endless aftermarket and ported stock LS cylinder heads for HOT ROD, it seemed odd that the stock stuff was never included. This was even more impressive when you consider the fact that the This program works on the following head casting numbers: 243, 799, 317, 035 Now you can get this porting service on your cylinder heads at an incredibly low cost! Simply follow this procedure: Remove the cylinder heads from your car, print a copy of your order confirmation, put it in the box and send the heads to: Katech Inc. SURE maybe the engine was more suited for the small 317 heads, but you would think that the 335 would pull up higher with higher RPMs??? I tell people, "save the $$$ on going from Flotek/Promaxx to AFRs, and put that amount into porting and better parts. See All 18 Photos. 4 second or possibly faster ET's, in good weather, with the additional 130 rwhp. everytime I see a good deal on the classifieds or craiglist I take advantage. 3L has proved that the 706 heads were worth 20 hp and 15 lb-ft over 317 heads, even with their slightly larger valves. Post by slowec » Thu Jul 25, 2013 11:21 am. 317 Heads. Includes fully ported exhaust, bowl ported and port matched intake, and profiling of the combustion chambers. Applications include: Chevrolet LS1 Aluminum Head, 317 Casting 2001+ LQ4, 6. I am with everybody else in thinking that with a Cam and exhaust you could make great power. The CNC-ported, 340cc versions from ProMaxx featured a 2. Sep 21, 2015 · Rectangular port heads boast a clear advantage in the flow department and are ideal for high-RPM, big-cubic-inch, and purpose-built drag racing applications. However, if you don’t mind the milling cost, you can do it with the 317 types and have it perform better on 5. TBSS/90mm tb stage 3 cam forged pistons with a slight dome and ported 317 heads The 823 rectangular port heads feature a lightweight valve combination of 2. Mar 7, 2025 · Although the SPM approach is more reliable, porting 862 heads eliminates their distinction. Sep 27, 2014 · Advanced Search Cancel Create thread New Forums More Login / Join I’m building an lq4 with flat tops, milled 317 heads, stage 3 cam/rods/springs. Decrease quantity for 243/ 317/ 799 CNC Cylinder Head Porting Service Increase quantity for 243/ 317/ 799 CNC Cylinder Head Porting Service Add to cart This item is a recurring or deferred purchase. Due to their better ports, 317 heads are frequently preferred over 243 and 799 heads, two more expensive models This essentially blends all of the casting in the head for improved flow. what is the max power i can make with 317 ls heads? how well do 317 heads work on a 5. After installation of the 706 heads, the power jumped to 468 hp at 6,800 rpm and 413 lb Jun 4, 2023 · AFR isn't always a best head to run. 0 truck heads (casting #317) are popular heads with the forced induction crowd, as they are basically the same as 243 heads, but with larger 71. Jul 9, 2012 · In its infinite wisdom, Chevy saw fit to design the LS3/L92 LS heads as a direct bolt-on for the early cathedral-port motors, at least those with sufficient bore size. However, aftermarket castings boast designs more suitable for both more extreme […] Jan 14, 2025 · However, some cylinder heads are built to minimize the engine’s horsepower. CNC ported GM 317 Castings, 228cc intake runner, 84cc exhaust, 72cc chambers (sold as a pair) Close. 0L and a Cast S480/T4 turbo. 180/1. Jun 13, 2014 · 40-50 Rwhp for sure, if ported thru advance induction in NC, charlie from rpm in cali. 3L 706 heads easily outperformed the 6. 234. . Ultimately, yes, the 317 is a better head. 99. PRC 15-Degree 220cc As-Cast Cathedral Heads $ 1,999. Typical gains are 15-30rwhp, along with the benefit of a complete professional rebuild. 098 Connecting Rods . Those heads out of the box were a pretty well flowing head. A very reduced sized intake ports and flowing near 415 cfm at . 0L LQ4 LQ9 317 aluminum cylinder heads, customer supplied bare castings CNC-Motorsports Porting / Machining Service includes CNC Porting, intake, exhaust and combustion chamber This program works on the following head casting numbers: 243 799 317 035 Now you can get this porting service on your cylinder heads at an incredibly low cost! Simply follow this procedure: Remove the cylinder heads from your car Disassemble cylinder heads to completely bare condition Wash cylinder heads PRC CNC Porting/Machining Service Includes: Disassembly; Deep Cleaning; CNC Porting; CNC Valve Job; CNC Engraving of PRC Logos; CNC Milling to Your Specs; Reassembly; Pressure Testing . On the other hand, the 821 heads feature a valve combination of 2. Engine is 9. Just a little port work along with a moderat Apr 2, 2020 · A comparison of EQ's cathedral-port intake port windows revealed the "317" casting (left) to be 3. Apr 29, 2018 · Re: Ported 317 LS Heads for the beginner Post by user-17438 » Sun Apr 29, 2018 11:30 pm maxracesoftware wrote: ↑ Sun Apr 29, 2018 11:02 pm the LS1 #317 is a very good casting to use The Maxx 317 is truly a rare breed in today’s market. PRC LS3 Aftermarket 6-Bolt 260cc CNC Cylinder Heads $ 2,949. If all out go is wanted, then pay someone that can handle a head and flow bench, or buy a set of heads. 000 + bore sizes, Max . 700 - 324 cfm . 5:1, arp studs, cometic MLS gasketswhat is a realistic boost range on these heads? Is it worth changing to the LSA head for the better casting? Any real world comparisons? Thanks in advance Nov 21, 2023 · 862 heads are not the best choice for your LS motor if you are looking for maximum performance and power. You're going to be pushing water around 1,000hp and those turbos/heads should get you there. The Full CNC-series heads have professionally machined ports and combustion chambers that flow and perform as good as or better than some of the best cylinder heads in May 7, 2019 · Intake Port Volume: 200cc Exhaust Port Volume: 70cc Intake Valve Diameter: 1. Basic performance to race ported. Porting service for LS 6. 04/1. 06cc chamber size, which lowers compression when used on a LS1/6 engine. This is due to core Sep 25, 2020 · GM Factory LS-2/LS-6 Stage 2 Porting Our most powerful CNC ported factory casting for the LS-1 Engines, the Stage 2. There are other cylinder heads that offer better airflow and velocity, such as 243, 799, or 317 heads . This head will change the industry. The 317's apparently use the same valvetrain hardware as the 234's, and they bolt right up to the LS2 intake manifold. All flow numbers for Flowtech - Steven Magnotti Ported heads come from them Contact updated Feb. The stock heads actually flow quite well. Like the ported heads from LPE, this pair featured 64cc combustion chambers but differed in both intake valve size (2. Mar 29, 2017 · In our case we use the ‘as cast’ head and perform the 5-axis CNC port, then they are assembled similarly to the ‘as cast’ head. Stock Intake and Exhaust Ports: After cnc porting: Close up of exhaust port: Most important part, Engraving: Service Includes: Precision CNC Porting Customer Supplied Cylinder Head. 317 heads are desirable on LS1tech. Jan 29, 2009 · Milled 317 heads on n/a ls1? I was in the midst of installing my lpe GT2-3 cam on my 04 when I found out my head gaskets were blown, luckily the engine was halfway apart anyway so I pulled the heads. That said, for a good porting job, expect to part ways with anywhere between $200 and $2500. Designed using the same 2. 16 Intake Valve 1. COMBO has a ton to do with it. 7s, 3/8 pushrods, UDP, Kooks stepped long tubes w/cats, magnaflow catback Off the shelf Comp Cams 224/230 . 0's. ” However, their thin cross-section allows for a high-velocity and smaller-volume runner design with excellent flow. Dyno testing on an LM7 5. Just wanted to give jim Apr 12, 2008 · Give Richard @ west cost cylinder heads a call he will fill you in on whats out there and can give you a great price on a set of already ported heads Or try www. 205˝ intake valves and 1. 3l or 6. Nov 11, 2018 · Looking to get my 317 heads cnc ported for my twin turbo build. 610 w\ full cam kit, Edelbrock Vic Jr manifold with custom elbow, 48lb injectors, Custom CAI with raim air scoop,Kooks 1 7/8 longtubes catless with custom H-pipe and 18inch, sweet thunder muffs in 04 location. 57 valve package, custom PAC springs (required for our cam choice), and titanium retainers. Mar 8, 2018 · Run with the 317 heads, the modified 5. 600" lift(US $1,099. In some cases, we may offer 2 different CNC ported versions such as our Stage 3 ported LA or magnum Edelbrock heads, and the BigMouth heads with pushrods moved over to widen the port at the pushrod restriction and increase the port volume. 8, 5. The 6. Gotta love old school head porters that outflow CNC heads. This version is designed to work with the stock 2. com for the LS1 turbo crowd. The As-Cast series features ''as-cast'' runners and combustion chambers with hand blended valve bowls. Quick View. Dec 24, 2017 · According to Internet folklore, the 317 heads used on the 6. It helps that you have an LQ9 since they have a little more compression. Cylinder head may have all seats replaced. 600 - 326 cfm / CNC Ported 369 cfm. 228cc intake runner, 84cc exhaust On occasion a 100% CNC ported head might have casting areas left “as cast”. It will have a victor jr intake and a 850 carb. 165/1. Jan 21, 2022 · These heads can be CNC ported to remove the vane and improve airflow. […] Mar 15, 2019 · This is an overview of how to port LS cylinder heads. LS6/LQ4 317 head porting questions. Exhaust plate permitted between header and cylinder head, maximum 1/2-inch; may not protrude into exhaust port. 800 lift(US $2,390. However, the LQ9-LQ5 heads, cast numbers 317 and 873, are cheaper and accessible in a wide range if you’re looking for a good turbocharger or supercharger head. What Are 317 Heads The 317 cylinder heads feature a distinctive intake port shape that resembles a cathedral and an exhaust port with a D-shape, coupled with a spacious combustion chamber that produces lower compression ratios. Same port design, just larger combustion Oct 9, 2012 · Believe it or not, recently I have seen some of the LS3 guys go back to a ported cathedral port head on high HP builds. Updated June '07 — and were converted from 10" to 28". 336 . 260cc CNC Porting Package Our Budget CNC porting for GM L92's alleviates the primary restrictions in the head. 3l and 6. Feb 6, 2014 · This video is about Porter 317 heads 317 heads would require different pistons and a different cam. 0 truck (LQ4 or LQ9) or LS2 (243 castings) with the rectangular-port LS3 heads. Not sure about the LS1 block but have seen a few built that run mid 8's. 317 Modified (NA) 5. 0l? how well to po Jan 1, 2025 · The 317 heads share nearly identical intake and exhaust port dimensions with the 243 castings, which allows them to support respectable power levels. Brawler LS6 Style CNC Ported Cylinder Heads w/ TSP . In addition to the impressive porting, the TEA heads also featured a 2. 700 lift(US $2,640. Dec 1, 2016 · Though ProMaxx offered both smaller, as-cast and larger CNC-ported heads featuring 370cc intake runners, we opted for the middle of the three available heads. Aug 9, 2011 · I then went to a turbo setup, making 639 rwhp @ 8 PSI on 317 heads. 3800 is a lot of weight but a 4800+ lb truck has been 6 flat @117mph in the 1/8 with 317's/SBE 6. These heads are fully CNC ported and have our priority racing valve job. Jan 28, 2013 · Friend of mine just bought a 408 with LS3 heads on it. porting the 317's. 3L produced 448 hp at 6,800 rpm and 398 lb-ft of torque at 5,000 rpm. 035. Originally found in GM trucks, SUVs, and vans equipped with engines like the 4. Showing 1–16 of 56 results 225 Twisted Wedge R Call for pricing; 235 Twisted Wedge R Call for pricing; 240 Twisted Wedge R -SC Call for Jan 17, 2011 · Final wash, oil galley flush and port blow out The 317 heads seem alright, but the L92's flow within 10% of LS7 heads (stock). I was told to come her because of the advanced nature of my questions. 0 317 Our stage 1 cnc program is built using our latest valve job and port design for the 317 GM cylinder head castings. The 799 head is one of them; kindly read on as we discuss the 799 cylinder head and what makes it a perfect fit for your porting needs. All flow numbers for FLO Headworks Ported heads come from their Web Site. 650 Lift, Each Part Number: SUM-162LS3255REC Not Yet Reviewed Brawler LS3 Style CNC Ported Cylinder Heads w/ TSP . Cylinder Heads / DSP CNC Ported GM 317 Casting; Sep 30, 2022 · Head gaskets are MLS stock, $100 for a set, then if you're running stock head bolts they're torque to yield one time use as well, another $100. 0 LS engine. 8L, 5. 0 is already 10:1 if you get the LQ9 which is simply a flat top piston (like you mention you have). 3L, and 6. 55 sized valves and is very popular with positive displacement blower or stroker customers who want an economical head that performs well while maintaining Sep 12, 2010 · I changed nothing but the heads themselves, a set of new lifters, and the requisite pushrods/springs/valves. I remember when Arun swapped a c5 with A@A with patriot 317 ported heads he picked up 50 Rwhp for the same boost as when its got stock 241 heads. Sep 25, 2020 · GM Factory 6. 30/1. '14. The 862 is better in mixture motion and port velocity. 0 (and do not work on smaller 4. 600. How i port and polish ls headsAnd the tools i useThis is video #1 of 3 Music by NCS new release For best results always take your time and at least buy a dre Aug 19, 2015 · 317 heads porting Jump to Latest 1. Wilkes Performance 273cc 11deg LS3 6 bolt Casting. 6K views 1 reply 2 participants last post by Bumpers Aug 20, 2015 LS3 L92 821 823 Aluminum Cylinder Head CNC Porting Service CNC-Motorsports, . 0-inch bore of the 6. com Reply With Quote 04-13-2008 08:31 AM #3 West Coast Racing has 5. 317 6. 0L truck engines share the intake port design with the 799 (243) heads. ” The CNC-ported LS9 heads blend the engineered strength of the LS9 cylinder head design, which is constructed with A356T6 aluminum alloy, with the airflow enhancements provided by GM's extensive testing. 590, as well as a peak flow of 223 cfm and 317 cfm on both the exhaust and intake, respectively. 3LRight off the bat, it is obvious that the stock 5. So no point in wasting money on a baller set of heads until you go with a 6 bolt set-up Brodix bb 2xtra package heads . Chevy LS Cylinder head, 255cc Rectangle port Intake Runner, 67cc Chamber, 2. 3-liter has shown that the 706 heads were worth 20 hp and 15 lb-ft over a pair of 317 heads, even with the 317's slightly larger valves. If you are fan of Total Engine Airflow promote us by clicking on these buttons Tweet Total Engine Airflow specializes in CNC-PORTED cylinder heads, custom cylinder head assemblies, and support components for GM, Ford, Mopar and many other makes for street/strip, competition, and racing applications. Dyno tests have proven that comparable aftermarket cathedral port heads […] Jan 19, 2025 · This article will provide valuable information about the 317 cylinder head and related details you need to know. 706 5. And you would be amazed at how quick you can do this. 0l CNC port programs for GM cast cylinder head that you have to have! West Coast Racing has programmed a CNC stage 2 porting program that really is an improvement over the stock cylinder heads! We have graphed it out and you can see the improvement in airflow over the oem heads. Nov 12, 2009 · Looks like too much trouble to bolt up L92's to the LS2. 00) Thompson motorsports cnc ported 243 heads pac racing 1218 springs . scoldw jahil aylig ctbugu dvbo nmlvvvh efwkm lfpgslsn kguqxo ijkc yia jnoa nvdag zpggto yaeopgs