We find out which factory LS head works best under boost in this back-to-back test of the 706 heads vs. the 317 heads. 398ci LS, TKX, QP 9 inch, Strange pro iron case, strange 35 spline axles, Spc front upper control arms, UMI front lower control arms, Howe ball joints, upper +.5 tall, CPP C5/6 spindles, Ridetech coilovers, C5/6 brakes, C7 …I knew the flow was the same just didn't realize gm put the 243's on the 5.3's. I better look at the driver side because I remember GTO's and vettes with 1 - 799 head and 1 - 243 head on the other side. My LS6 has 10.5:1 with 243's and I love it. The 09' has great response also eventhough I haven't tuned it yet. 97 GMC, 2002 LS6.2004 #243 GTO heads vs 2002-2004 #234 LS6 Corvette heads. New guy here, but I've been driving GTOs since I bought my first, a 1970 400 w/THM, back in high school in 1975. I presently own a 2001 Corvette with an all stock LS1 and I've been wanting to bump up the horsepower from 350 to 420-450 (more would not disappoint me).The 799 and 243 casting Cathedral-port cylinder heads can be CNC ported to flow close to the aftermarket heads. With a bigger cam you can mill the heads for up to 10.8 compression which runs on pump gas. ... There is no reason to put the weaker 862 head on an L33 when the engine comes with the best flowing cathedral port heads GM made. The L33 ...But no matter, your LQ9 is the gold standard of solid GEN 3 builds. You are going to have to get those LS6 heads ported, a good shop is West Coast Cylinder Head. Richard is the guys name. ANd they even have a swap out for your exact 317 head 250cfm to just over 300cfm. For $1500 exchange, $1800 outright. Pricing.TEA stage 2 862's or 243's? Jump to Latest Follow 21 - 35 of 35 Posts. 1 ...Jul 10, 2022 · You are much better off with the 706/862 heads from a compression standpoint. Also, the port velocity on the 706/862 head is much better than the 799/243, which will help you with the small bore of the 5.3. The 706/862 respond very well to a light runner cleanup and a good multi angle valve cut.Expedited Core Exchange - We will ship you a set of CNC ported heads fresh out of the machine and set up to your cam specs once the order is placed. Once your usable cores have made their way to us, LME will refund the cost of the cores. Current GM LS1 243 Cylinder Head core value is $250.00. **No matter what method you choose, once order is ...243 04 up LS6 aluminum center bolt 5.7 ***These castings were also used around 05 in truck applications*** 862 99 and up 4.8-5.3 Truck heads 706 99 and up 4.8-5.3 Truck heads 799 05 and up 4.8-5.3Truck heads ***reportedly came on a few corvette's too*** These are basically 243 Heads 873 99-00 LQ4 6.0 Iron center bolt headsWe have a few options you can purchase such as a pair of Stage 1, Stage 2, Stage 3, or Stage 4 LS 243/799 Cathedral casting 5 axis CNC Porting with stainless valves and WP .660 dual race springs with WP titanium retainers. These heads have been disassembled, inspected, cleaned, 5 angle valve job, and milled slightly to clean up the heads.ForceFed86. 2515 posts · Joined 2012. #4 · Jul 30, 2014. Sure they are. They just flow less. At .050 on the same flow bench a 243 flowed 251/176 VS a 862 at 218/163. One article I read showed a direct head swap with no other changes was worth 24ftlb. The CC in the 862 is 61cc VS the 243's 64cc I believe. So you need to factor that in as well.The first has to do with port shape. The LS6 and the later LQ9-LQ4 heads used reshaped intake ports and D-shaped -- as opposed to oval-shaped -- exhaust ports for better flow: 200 cfm intake and 70 cfm exhaust for the 241's, and 210 intake and 75 cfm for the 243's. The second major difference is that the LS6 heads used hollow, sodium-filled ...I would think a 243 head is a 243 head, I think I read that the 243 was used on the LS6 Z and all LS2 motors had the 243 heads. Mr.Bill Reply Like. 09-27-2011, 08:43 PM #3 Eddie 70. Race Director . Member Since: Feb 1999. Location: Lenoir City Tennessee. Posts: 19,658 Likes: 59 Received 29 ...The 862 heads are pretty good because they can deliver better compression after a porting job. However, the cylinder heads may not flow well compared to 243 heads. Also, 706 heads are considered to be superior to 826 cylinder heads. 826 cylinder heads are not as sophisticated as some of their counterparts.The first has to do with port shape. The LS6 and the later LQ9-LQ4 heads used reshaped intake ports and D-shaped -- as opposed to oval-shaped -- exhaust ports for better flow: 200 cfm intake and 70 cfm exhaust for the 241's, and 210 intake and 75 cfm for the 243's. The second major difference is that the LS6 heads used hollow, sodium-filled ...Received 26 Likes on 26 Posts. I took my 243 heads and had them cleaned up ( polished ) cleaned up ruff edges, but not ported. Had them milled to about a 62-61.5 cc chamber or something like that. run a 224/224 581/581 112+4 comp cam. comp 918 springs, comp rockers. Smith brother push rods.The 799 heads are superior to the 243 heads for automobiles because it is more efficient. Because it has a larger capacity, the Chevy 799 heads are better than the 243 heads. Most cars with 4 or 6 cylinders can use the 243 heads. Compared to its rival, the 799 cylinder head, it has more ports for greater air intake and exhaust flow, resulting ...Last Updated on Aug 16, 2023 By Paul Lucas. There are three main differences between 241 and 243 heads. The first is the size of the combustion chamber, the 241 has a 67 cc, and the 243 has a 65 cc. The second is the port shapes. The 241’s oval-shaped port has a 200 cfm intake, and the port on the 243 is D-shaped and offers better flow.Re: 5.3 Chevy 862 valve job porting questions. by CGT » Fri Aug 30, 2013 1:43 pm. The 862's I have seen have the throat WELL over 90% with no material for a bottom cut. It will take a bigger valve to be able to get a decent valve job on that head, judging from the ones I've seen. SMITHBERGRACING. Guru. Posts: 1100.I was thinking more along the lines of a ported 243 casting with a fast 90 (i figure at least $3300 for the whole kit and kabootle) figuring 2K (lets use livernois stage 3R's for pricing purposes) for the heads and 1300 for a ported fast. I havnt seen many guys go with a setup quite like this so im not sure what the powerband will look like ...863. Rectangle. 4.750" +- 0.003". 12604861. 12610716. 12675872. Share this article. We've tried to boil down the GM part numbers, casting numbers and other LS cylinder head information into an easily usable (and ideally definitive) cross reference. Note that we're not perfect and some of this data may not be perfect so use it for what you will.Gender:Male. Location:SoCal. Owns:SS. Color:Victory Red. Year:2006. Drivetrain:2WD. Posted January 9, 2008. the 317 and the 243 stock, flow the same cfm, they just have different chamber sizes. you should consider a converter too, so ported heads and a 220ish cam and coverter will be a nice set up. Quote.I've seen plenty of 243/799 head combos on nearly-new (read: all original) GenIV 5.3s. Reactions: Sintek, RAMurphy and Sam Harris. Feb 9, 2023 #9 mattbta Full Access Member. Joined Jun 19, 2012 Posts 1,055 Reaction score 1,900 Location Frisco, TX. Mine has an 862 and a 706. My factory 706's cracked. Got a refurb set of 706's and one cracked ...The factory-built motor dished out about 430 horsepower right out of the gate, and the cylinder heads play no small role in that impressive output. The LS3 heads hit the flow bench. The LS3's 319-T5 aluminum alloy cylinder heads use 2.165 in (55.0 mm) intake valves, 1.59 in (40 mm) exhaust valves, and a 15 degree valve angle.We have a few options you can purchase such as a pair of Stage 1, Stage 2, Stage 3, or Stage 4 LS 243/799 Cathedral casting 5 axis CNC Porting with stainless valves and WP .660 dual race springs with WP titanium retainers. These heads have been disassembled, inspected, cleaned, 5 angle valve job, and milled slightly to clean up the heads.Why are Chevy 706 Heads better than 317 or 862 Heads? 706 Heads Vs. 317 Heads; Most people tend to prefer 317 heads as they have improved ports, same as 243 and 799 Heads, which are more …Our fellow tech writer and dyno-flogger Richard Holdener reports a gain of roughly 15 hp with stock 5.3-liter heads on a 6.0-liter. Our 5.7-liter head test bumped the average power by 9 hp but ...Showing the port work on my 862's setup for a small 4.8 build. Goal 375-425hp at the crankshaft prior to the Turd-Bo turbo install! 👍862 castings 20022.00/...BARE GM LS 243 HEAD - 4.8L, 5.3L & 6.0L. Generation III V8 cathedral intake port cylinder head. Casting 12564243. For truck, van, SUV and perfomance applications. Used on LS6, L33, L20, LH6, LY5, LMG, LC9,LS4, LH8, LS2, LFA, LZ1 engines. Generation III cylinder head for V8 truck, van, SUV and perfomance applications often called an LS6 head. It ...5.3 vs Vortec 350 in a Jeep; Changed direction on project. A1000 fuel regulator questions; Fuel boiling.... Breaking up at 5k and above RPM; ... 862 vs. 243 Heads; Holley Tunnel Ram; Easiest way to rig starter? perf rpm; 5.3 teardown/build; started my swap; Help with Rad Fans; FYI for Performer RPM users!!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). The biggest difference between the 317 cathedral-port heads and the LS3 heads was the port shape and …The LS engines with 799 heads are 5.3L and 4.8L. The sophisticated architecture, cathedral-shaped port, and smaller combustion chamber work amazingly on these truck engines. The smaller combustion chamber with a higher compression ratio offers increased power output. The 799 LS heads boost horsepower up to 25 hp.Newly reworked 243 heads versus AFR heads. Hi guys, I have a 2006 C6 A6 with 145,000 miles on it. Mods include K&N breather, LG Long Tube Headers, and a Circle D stall converter. I recently swapped my LG G5XB cam for a new LG G5X3 114 cam. I have factory 243 heads that have just had a competition valve job including new guides, valves, Comp 921 ...Curious on what factory head would be better on my 2002 4.8. Factory has the 862 heads. I’ve been offered a 5.3 block with 243 heads on it for $300. Would the stock 243 heads work better on it than the 862 heads? Obviously they need to go to the machine shop to be looked over but without any alterations to the stock form, which is the better ...821's and 5364's are identical as a bare head. You can swap them without a difference. The only difference is the 821's can be a LS3 head and have the lighter intake valves and yellow valve springs but still them same head and flow. The only time you are going to see a performance difference is when there is a casting shift that affects the ...Re: Getting ready for my LQ4 Basic H/C/I Ported 862 head flow numbers vs baseline. « Reply #30 on: April 24, 2016, 10:01:39 PM ». No. We were only doing 806/853/241 heads then. We got a set of 243 heads right before the C5 Z06 came out. That 862 head is down 20+ hp on a 243 before you even start. It needs the bigger valves for …It still used 799/243 heads but also utilized variable valve timing and had flex-fuel capability. Chevy also used a 5.3L engine that was only in vans produced from 2010 to 2014, known as the LMF engine, identified by a number 4 in the 8th digit of the VIN. ... some include 1218 springs and the Elgin 228/230 cam. If your truck has 862/706 heads ...IMO, a 243 CNC head and LS6 intake (or spend the chese for a FAST 92) will definately make a great street motor. i made peak power at 6000 rpms and shift at 6600 rpms. its a mule and could last forever if i didnt decide to spray it all the time . 1999 Pontiac Trans Am. Save Share.GMPP CTS-V Race lifters C5-R timing chain Improved oil pan baffle. That's it. There are some more details in my build thread, but it's basically a more durable, stock LS1 with a cam. It made 401/401 with a safe tune. It is good when the 100 treadwear tires warm up get sticky. And yes, non offset rockers from a 317 head will work on the 243 …My 2007 came with 243 heads stock. the 862's are off the early 4.8-5.3 motors after about 99 I believe. I also believe texas speed used to have the 2.05 valve opton on those heads at one time. I run 2.04 valves on mine. 12-30-2010, 08:54 AM #7.The 243 Heads are cast iron cylinder heads that have been CNC-machined to create larger intake and exhaust ports. The combustion chambers have also been machined to be smaller, which increases the compression ratio. While the 243 heads are not the newest or best option out there, they offer a great value for the price.40 posts · Joined 2018. #46 · Jan 20, 2020. Your 6.0 block is a 4.00 inch bore, you have to run a LS3 type head 5.3 and 4.8 have smaller bores. There are tons of heads out there yours probably came with the 799 castings like my 6.0 did.Compression Ratio. The 862 head has a smaller combustion chamber as compared to the 706 engine head. It is due to this difference in the size of the combustion chamber that the compression ratio of 862 is higher. This slightly improves the engine performance and the 862 engine head seem to be standing at a better pedestal as compared to the 706 ...let's talk tech, anyone ever see a set of stock 243 heads flow 270+ cfm? we compared 243 heads to 862 heads, ported, chamber work & big valve.what i have learned is that running plain 243 unmilled heads 7.4 pushrod is fine. the 243 head with light weight valves requires you to run a shorter pushrod,or if the deck surface is milled. possibly a 7.35 length rod,but im not sure. would have to be measured for proper length. Like.It still used 799/243 heads but also utilized variable valve timing and had flex-fuel capability. Chevy also used a 5.3L engine that was only in vans produced from 2010 to 2014, known as the LMF engine, identified by a number 4 in the 8th digit of the VIN. ... some include 1218 springs and the Elgin 228/230 cam. If your truck has 862/706 heads ...863. Rectangle. 4.750" +- 0.003". 12604861. 12610716. 12675872. Share this article. We've tried to boil down the GM part numbers, casting numbers and other LS cylinder head information into an easily usable (and ideally definitive) cross reference. Note that we're not perfect and some of this data may not be perfect so use it for what you will.799 LS Engine Cylinder Heads are some of the most recent cylinder heads on the automotive parts market. The cylinder cast architecture is with a semi-permanent mold method. The 799 cylinder heads are in the similitude to the 2004 LS2 cylinder heads due to the triangle casting marks similarity. However, unlike the 243 heads, they do not require ...The 317s slightly larger runners and valves won't give you 4%. So if we were talking NA, I would agree the 862 would make slightly more power than a 317. Once you add a turbo though everything changes. With that 1pt of compression drop you can add a good 5-7psi.243 heads on 5.3l. Thread starter riccotxtre; Start date Jun 26, 2020; Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission. Jun 26, 2020 #1 R. riccotxtre TYF Newbie. Joined Jun 19, 2015 Posts 14Showing the progress Porting the 862's for my Turbo 4.8 project. Yes it's a slow process and I limit how much I can do each day.I'm in the dirtiest portion ...Aug 7, 2023 · For the 862 heads, the intake valve size is 1.89 inches and the exhaust valve measures 1.55 inches. The 706 heads, however, feature an intake valve size of 2.00 inches and an exhaust valve size of 1.55 inches. In terms of port volumes, the 706 heads have larger intake ports.If the 706, 243, or the later 799 is the go-to head for any engine, the 317 is just right behind. It's designed with the same ports as the 799 and 243 types but with larger chambers. ... 706 Vs. 862 Heads. The 706 model is made to be superior to the common 862. The semi-permanent mold (SPM) method is a consistent process. ...The 799 and 243 casting Cathedral-port cylinder heads can be CNC ported to flow close to the aftermarket heads. With a bigger cam you can mill the heads for up to 10.8 compression which runs on pump gas. ... There is no reason to put the weaker 862 head on an L33 when the engine comes with the best flowing cathedral port heads GM …lt1z. 30920 posts · Joined 2007. #6 · Mar 12, 2015 (Edited) A 317 head on an LS2 will be 10.0:1. A 243 on a LQ9 will be 10.9:1. Only major difference is combustion chamber cc. I would not go with less then 10.0:1 compression on a 2300. Mill a set of 317s to 70cc, run an LS9 gasket and head studs. C6 M6 Vortech 857/725.Our fellow tech writer and dyno-flogger Richard Holdener reports a gain of roughly 15 hp with stock 5.3-liter heads on a 6.0-liter. Our 5.7-liter head test bumped the average power by 9 hp but ...Intake and Exhaust Ports. The intake and exhaust ports on the 243 heads are larger than those on the 799 heads, which allows for more air and fuel to enter the engine. This can result in higher horsepower and torque output. However, the smaller ports on the 799 heads can provide better velocity and airflow at lower RPMs, which can be beneficial ...The 862 head is commonly utilized in high-performance cars, racing, and sports cars. It’s also found in some luxury and sports cars. The 862 is a 12-valve design that utilizes two intake valves per cylinder and one exhaust valve per cylinder. The combustion chamber volume is 84cc for the 862S, 83cc for the 862C, 84cc for the 862F, 82cc for ...The price difference for 799 an 241 heads is because the 799 is a twin to the 243 an have better ports an 64.54cc chambers where the 241/853s have not as large of a port an are 67cc..your 862 is actual the smallest chamber head being 62cc but their down side is smaller valve size an slightly less flow then 241/853 heads..Vehicle enthusiasts argue about 243 heads Vs. 799, as well as 243 heads Vs. 862 heads . However, if you desire improved horsepower with excellent power output, the 243-cylinder head is a perfect choice.We Step Up The Power With A 468ci Engine To Log The Performance Of Nine LS3 Rectangle-Port Heads. ... 243. 0.700 . 359 . 246. Like the offerings from Mast Motorsports, the Dr. J's CNC LS3 heads ...Like AFR's other SBC cylinder heads, the Enforcer is available in both straight and angled-plug configurations. The 195cc intake runner flows 251cfm at .600 inch of lift, while the 76cc exhaust runner moves 197cfm at the same lift. Like both of the other small-block options, the SBC variant features 2.020-inch stainless intake valves and 1. ...If you are just installing stock heads with no work, forget the 5.3 heads and just get a set of decent 243 heads which will still bump CR up 1/2 point on the LS1 (64cc combustion chambers compared to 66 CR of the 241 heads). 2004 torrid red with red interior A4 GTO (1 of 499)HOW MUCH POWER ARE PORTED HEADS WORTH? HOW MUCH POWER ARE REC-PORT LS3 HEADS WORTH ON A 6.0L? DOES A 408 STROKER NEED BIGGER HEADS? CAN I RUN 317 HEADS ON MY...Last Updated on Aug 16, 2023 By Paul Lucas. There are three main differences between 241 and 243 heads. The first is the size of the combustion chamber, the 241 has a 67 cc, and the 243 has a 65 cc. The second is the port shapes. The 241's oval-shaped port has a 200 cfm intake, and the port on the 243 is D-shaped and offers better flow.Aug 24, 2022 · The 862 head is commonly utilized in high-performance cars, racing, and sports cars. It’s also found in some luxury and sports cars. The 862 is a 12-valve design that utilizes two intake valves per cylinder and one exhaust valve per cylinder. The combustion chamber volume is 84cc for the 862S, 83cc for the 862C, 84cc for the 862F, 82cc for ...Curious on what factory head would be better on my 2002 4.8. Factory has the 862 heads. I’ve been offered a 5.3 block with 243 heads on it for $300. Would the stock 243 heads work better on it than the 862 heads? Obviously they need to go to the machine shop to be looked over but without any alterations to the stock form, which is the better ...The 862 heads are inferior to the 706 heads in terms of compression, and they don’t also flow well like the 243 heads because it doesn’t have other competitive features; however, depending on your car’s needs and budget, the 862 cylinder heads might be a good port for you.Which Stock LS Head Is Best For Building A Boosted Turbo LS Combo? 317, 799, 706, 241, 243, or 862? Feb 23, 2021 Chad Reynolds 1320 Engine Tech, ... Cause I don't. I know I have a couple sets of LS heads sitting in the garage, but could NOT tell you for certain which ones they are. I think one set might be 862 but I can't be sure. I'd ...I then went to a turbo setup, making 639 rwhp @ 8 PSI on 317 heads. I was anticipating some 10.4 second or possibly faster ET's, in good weather, with the additional 130 rwhp. 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.Chinese authorities are investigating Meng Hongwei, who has been missing since late September, for taking bribes. Two years ago, Meng Hongwei became the first Chinese person to hea...Run with the 317 heads, the modified 5.3L produced 448 hp at 6,800 rpm and 398 lb-ft of torque at 5,000 rpm. After installation of the 706 heads, the power jumped to 468 hp at 6,800 rpm and 413 lb ...706 5.3L HEADS vs 241, 799/243 vs 317s. WHICH HEADMAKES MORE? We compared the four most popular stock LS heads in a back to back shootout. We ran the 706/862...I used a Comp 219/227 .607/.617 (ish) cam on a 2008 5.3L w/ longtubes and stock 243 head. Iit picked up 46hp over the stock cam. The world's best cam combined with a poor set of heads will produce an engine that's a dog. But bolt on a set of great heads even with a poor cam, and that engine will still make great power.Intake and Exhaust Ports. The intake and exhaust ports on the 243 heads are larger than those on the 799 heads, which allows for more air and fuel to enter the engine. This can result in higher horsepower and torque output. However, the smaller ports on the 799 heads can provide better velocity and airflow at lower RPMs, which can be beneficial ...We Step Up The Power With A 468ci Engine To Log The Performance Of Nine LS3 Rectangle-Port Heads. ... 243. 0.700 . 359 . 246. Like the offerings from Mast Motorsports, the Dr. J's CNC LS3 heads ...Apr 14, 2012 · 3012 posts · Joined 2008. #1 · Apr 14, 2012. I have a 2004 Aluminum 5.3 with 70k miles that has 862 heads on it. I also have a set of 243 heads off of a 2009 Aluminum 5.3. Which heads should I use? I've been told the 243's flow better and the 862's supposedly raise compression .5 a point.Which Stock LS Head Is Best For Building A Boosted Turbo LS Combo? 317, 799, 706, 241, 243, or 862? Feb 23, 2021 Chad Reynolds 1320 Engine Tech, 1320 Spotlight, Apex Engine Tech, Apex Spotlight, XL Engine Tech, XL Spotlight Comments Off on Which Stock LS Head Is Best For Building A Boosted Turbo LS Combo? 317, 799, 706, 241, 243, or 862?. Suicidal Racing. 26755 posts · Joined 2006. #6 · Jul 31, 2012. Maybe iPros And Cons Of Doing A 243/799 Cylinder Head Swap On The L Aluminum vs Iron Heads for 383 Stroker. When it comes to choosing between aluminum and iron heads for a 383-stroker engine, there are some factors to consider. ... 862 vs 706 Heads: Friendly Comparison to Find the Best; Best Cam for 5.3 with 706 Heads: Top Picks for Enhanced Performance; CNC Ported LS 5.3L 706 / 862 Cylinder Heads, Customer Su The 706 Vortec heads are even slightly superior to the commonly found 862 heads. The reason is that the 706 heads are SPM ... these are basically 243 heads; See All 5 Photos. Vital Specs for 706 ... I then went to a turbo setup, making 639 rwhp @ 8...
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