862 heads: These are also compatible with 5.3 engines, similar to 706 heads. However, they offer slightly less power potential. 243 heads: A popular choice for LS enthusiasts, they provide higher power gains when matched with the right cam. Cam swapping with 5.3 engines typically benefits from using LS3-type springs. These springs improve valve ...Regarding finish, many reviews say 799s deliver a smoother one than its rival when pitching them against each other. 823 vs 243 Heads. As mentioned about the LS 823 heads specs, its bigger intake port owns a 70cc, whereas the common 243 L6 cylinder heads have basically a smaller volume at 64cc.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)Jan 5, 2023 · The 243 vs. The 799 Cylinder Head. As you have most likely caught on by now, these two cylinder heads are practically the same. The main difference between the 243 and 799 cylinder heads is that the 243 was used on older engines from GM Research, while the 799 has been used on newer engines from multiple manufacturers.The 243's have bigger valves which do better on 4.0" and larger bores. On the smaller 3.898/3.78" bores of the LS1/6 & all 5.3/4.8's the 706 are very decent. On a 4.00" bore of an LQ4 though it is splitting hairs. On the same cam, on the same engine, the heads are going to perform within +/- 5hp/5tq of each other, it is almost meaningless.A comparison of EQ's cathedral-port intake port windows revealed the "317" casting (left) to be 3.19 x 0.965, while the "243" unit was 3.149 x 1.035. Both ports weigh …The primary benefit of porting and polishing 243 heads is improved airflow. This allows for better combustion, resulting in increased horsepower and torque. Additionally, porting and polishing can lead to improved fuel efficiency, as the engine is able to more effectively use the fuel it receives. If you’re looking to improve the overall ...Get ready to feel the G-forces as we navigate the exhilarating terrain of power and performance. 862 LS Heads aren’t just components; they’re the driving force behind an automotive revolution, and the journey has only just begun! DIY Adventure: Installing 862 LS Heads Like a Pro. Time to get hands-on, gearheads!Do you know what a Phillips head screwdriver looks like? Find out what a Phillips head screwdriver looks like in this article from HowStuffWorks. Advertisement The Phillips head sc...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.So how do 862 heads compare against the factory heads these engines come with? The 5.3L LM7 crate engine from GM trucks feature stock 243 heads. 243 …The 862 Cylinder Heads. Features and Specifications. In contrast to the 243 heads, the 862 cylinder heads are typically made of cast iron, which makes them heavier but also more durable. They have smaller ports compared to the 243 heads, which can limit airflow to some extent.The cc for the piston is entered as a positive number on a -cc Dish or Flat top piston and a negative number on a dome piston. This seems very confusing but it is because even though it is a -cc on the piston, those same cc's are gained in cylinder volume.The 862 heads are an excellent choice for any GM vehicle with an LM7 engine. Although the design is meant for high-performance settings, it performs well in the Avalanche, Express, Silverado, Sierra, Yukon, and other trucks or SUVs from the late 1990s to about 2007. You know if you've got an LM7 engine by looking at the eighth digit of the ...But, the combustion chambers are bigger than the 5.3 heads. You need to mill the 243 heads about .020" to keep the compression ratio the same. 2004 torrid red with red interior A4 GTO (1 of 499) TR-230/236 cam/TEA ported Trick Flow 215 heads/4" CAI/100mm MAF/ported FAST 90/Kooks/Magnaflow.I flow a stock 706, 862, and 317 LS Head and share the numbers.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 ...The 243 heads are, as far as i know, the best factory casting to go with based on the chamber design. Even though our stock heads flow very close to them(or the same), the 243 heads are supposed to have a quench pad in the design and offer better compression. The info i have lists the 243 heads at 65 cc so with the stock gasket you would be ...May want to read through here on the OEM head, just for some reference on the 243 vs. 317 heads on any short block larger than 6.0 especially if you plan to go the boasted route. 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.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 241 castings feature 205cc intake ports, 70cc exhaust ports, and a 2.0/1.55 valve combination. The hot factory heads would be the LS6 (243 castings), but even the stock LS1 heads can be made ...Oct 25, 2012 · If so, the 862 has a tiny 1.9 intake valve. The 317 head has 2.0 valve and a larger intake runner cc, like the LS6. The 862 in a good bench make 220ish cfm, 317s as much as 257 or so. Just has a larger combustion chamber.If so, the 862 has a tiny 1.9 intake valve. The 317 head has 2.0 valve and a larger intake runner cc, like the LS6. The 862 in a good bench make 220ish cfm, 317s as much as 257 or so. Just has a larger combustion chamber.Are the 799/243 that much better ported , then the 862 ported with bigger intake valves? Heads are for a turbo car running M1. Thanks Mike. in this thread in this sub-forum in the entire site. Advanced Search Cancel ... 862 5.3 heads. Jump to Latest Follow 1 - 3 of 3 Posts ...118. Intake valve is 2" on the 241, exhaust valve is same size as the 862. If planning on 241 heads on a 5.3 you will lose compression and hp. The Fleet... 2003 Suburban- 5.4 L59 331CI 10:5.1 Compression -Built by ME. 2004 Avalanche- 5.7 LS1 -NOT built by me. 2005 Silverado RCSB- 5.7 LS6 -Built by ME. Reply With Quote.The valves on LS3 heads are designed to be larger than those on stock LS heads to improve airflow, leading to increased power output. Standard valve sizes for LS3 heads include 2.165 inches (intake) and 1.590 inches (exhaust). However, it's not uncommon for LS3 heads to feature even larger valves. For example, some aftermarket LS3 heads may ...The 799 heads will need to be milled a bit to get the compression ratio back to where it needs to be. That will determin what pushrod to go with. The stock heads should be something like 61.15 cc. The 799 heads should be 64.45. . 1994 SFBD extcab longbed 20/22 406sbc . Project thread.You could bore to the LS1 pistons run them and get a set of ported 243's. Add a Fast 90mm intake, cam, and you have an 400hp iron block LS6. Thats easily a 100K mile motor. For a stock 5.3L port the heads, cam, and a LS6/Fast intake and it might make 400hp on a engine dyno. But would make 300-325hp at the wheels.Upgrading LM7 Cylinder Heads. The stock heads can be CNC ported for more airflow and milled up to .030 in. for more compression. Flow numbers can be as high as 325 cfm at .600 lift. Lightweight hollow stem LS3 valves can be cut to 2.000 in. to fit the seats. Between the light valves and better springs, the engines will pull cleanly to 7000 …Even stock 243 heads flow great. AFR did a comparison between many different heads vs their AFR 215 & 225s on another site and the stock 243s stepped up hard even matching the 225s flow at .550 lift and besting the 225s at .600 lift (albeit on a 4.125 bore which is pretty big, LS1 is 3.90 and LS2 is 4.00).The LS6 also received better (243 castings) heads, a slightly more aggressive cam, and a much improved intake manifold. The LS6 cam is the most aggressive cam GM put out for cathedral port headed ...6.0L (LQ4 and LQ9): Upgrading these larger engines with 706, 862, or 243 heads requires a single-pattern cam to optimize power gains. Cam specs play a vital role in compatibility as well. For example, a single-pattern cam with 224 duration and 112 LSA works best with mildly ported 706 heads. Comparative Table. Engine 706 Heads 862 …Sep 1, 2017 · Remember, not all 243 heads are LS6 heads, but all LS6 heads are 243 castings. True LS6 heads will have the stainless steel hollow-stem valves. ... 706/852/862 '99-up 4.8L-5.3L truck heads - 61 ...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 ...Just picked up a set of 862 5.3l heads for $100 and was wondering how well they will work for me. I have a forged 346 and the pistons have a small dish. I haven't done the math but the CR is around 9.2-9.4:1. I want to bring the CR back up to around 10:1. My plans are to hog the heads out and throw in some big valves and have them milled to get ...Mar 11, 2023 · 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 ...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.45 posts · Joined 2006. #4 · Apr 12, 2010. I'll recommend TFS 215 heads and a 224/228 comp cam. A friend of mine has this package and I was really impressed. With a ported fast he made 450 rwhp and the car idled and drove great. It was actually a little tame for my taste, but sounds like what you're looking for.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 …Find many great new & used options and get the best deals for Ls1 Stainless Steel Valve 2.02" Intake for 243 799 241 317 862 706 Performance at the best online prices at eBay! Free shipping for many products! ... item 1 GM 243 LS1 LS2 LS6 Gen 3/4 CYLINDER HEAD PAIR COMPLETE REBUILD NO CORE CHARGE GM 243 LS1 LS2 LS6 Gen 3/4 CYLINDER HEAD PAIR ...Do you know what a Phillips head screwdriver looks like? Find out what a Phillips head screwdriver looks like in this article from HowStuffWorks. Advertisement The Phillips head sc...The all new PRC aftermarket casting LS3 heads are the perfect option for customers looking for the ultimate in LS3/L99/L92 cylinder head technology. The 13-degree valve angle will allow for the ability to run more compression and larger camshafts thanks to additional piston-to-valve clearance!! Lift. Intake Flow.Remember that the '461X heads were used in 1961, 1962 and 1963 with valve sizes 1.94/1.50 only. The revised 461 heads were available starting in 1964 models with either 1.94/1.50 or 2.02/1.60 valves, depending on application. The later 461 or 462 heads would be my choice for a nostalgic look and high performance.Engine Technical. Engine Tech And Modification. LQ9 build cam suggestions. I just got my 4x4 T56 swap completed and now I'm planning a nice NA build. Through research I've found that the 243 heads and TBSS intake are a nice combo with CR around 11:1, and basically my whole setup hinges on the cam selection.Here's a quick data sheet on the specs of 799 heads. Due to the similarity, 243 heads should follow the same characteristics in normal situations: Combustion chamber volume: 64.45cc. Intake port volume: 210cc (sometimes seen as 209cc too) Exhaust port volume: 75cc. Intake valve diameter: 2.00 inches.Aug 18, 2011 · 241 was used on 01-04 LS1 engines. They both have a 66.67 cc combustion chamber (10.1 CR), 200cc intake runners, and 70cc (round) exhaust ports. The 243 head is the 01+ LS6/LS2 head. It has a smaller 64.45cc chamber for more compression (10.5 CR on LS6), 210cc intake runners, and 75cc D-shaped exhaust ports.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 headsMay 7, 2023 · Street Performance of The 706 Head. It’s worth noting that the 706 heads have a larger combustion chamber than the 862 heads, which measures at around 71cc. While this might sound like a disadvantage, it can actually be helpful for engines running on lower-octane fuel or those using forced induction.Feb 9, 2022 · 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 head? Engine is stock other than cold air intake.Another thing to consider is the life span of the MTI springs. The stock GM springs are guaranteed for three years, or 36,000 miles but generally last the life of the engine. Would you have this assurance with the MTI springed heads. Below are some GM numbers for 243 heads as a comparison. Stock CNC'd LS6 heads I E.100 .200 147 111WHAT STOCK LS HEAD MAKES THE MOST POWER? WHICH CAM SHOULD I RUN IN MY 6.0L? WHAT IS THE BEST STOCK 6.0L CAM TO USE? STOCK 6.0L UPGRADES! ARE THE …Chevrolet LS rectangle port heads need at least 4.00 bore. 5.3 and 4.8 are 3.78". LS7 heads require even larger. All 4.8s, 5.3s, and 5.7s came with cathedral port heads. Like mentioned, the square port heads were not put on any engine with a bore smaller than 4".I compared a set of stock 799/243 cathedral-port heads vs the 823 LY6 rec-port heads on an LY6 short lbock. The motor was equipped with a healthy Comp cam an...Aug 1, 2023 · The 862 Cylinder Heads. Features and Specifications. In contrast to the 243 heads, the 862 cylinder heads are typically made of cast iron, which makes them heavier but also more durable. They have smaller ports compared to the 243 heads, which can limit airflow to some extent.The AP220SP is the biggest 23* head All-Pro has before you get into raised runner designs. It is also standard valve spacing. Flow numbers @ 28" of water. All figures in CFM. All-Pro AP220-SP-23* --- ~$3,350 (uses standard valve train and fully CNC'd runner) Intake 219cc Exhaust.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 ...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.320. Exh. 111. 153. 193. 209. 219. 221. Our fully CNC'd 243 heads give your choice in stock 2.0intake/1.550 or upgraded 2.02Intake/1.600 exhaust with an intake flow of 320cfm and an exhaust flow of 221cfm.But as for the 5.3/4.8 heads, they used the same cylinder heads, identical. The only difference from the 706 and the 862 heads, are the way they are made. The 862 heads are sand cast, and the 706s are SPM (Semi permanent molded), but with just a bit of machine work, the difference between the two is null.51 posts · Joined 2011. #1 · Feb 22, 2012. Are the 5.7L 243 Casting Number Cylinder heads Direct Bolt on for a 4.8/5.3? StrokerAce03;5114860 said: Basically its just a bastardization of parts to create an oversquare engine that should scream at high rpm and rev to the moon. BE DIFFERENT.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 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 ...To 2007 head issues #243 vs. #799. C6 Tech/Performance - 2007 head issues #243 vs. #799 - I read a thread not long ago on C6 general about a difference in the heads on the born in Oct. 06 C6's that GM used, they used #799 heads as opposed to #243 heads. The person who wrote the thread said his numbers on the dyno where significantly off from ...Brawler LS3 Style CNC Ported Cylinder Heads w/ TSP .660" Spring Kit and Titanium Retainers $ 1,836.99. PRC 15-Degree 220cc As-Cast Cathedral Heads $ 1,820.69.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 …While this is the case, all of the work he put into doing that with stock 862 heads is barely worth the gain. He would have been better off slightly milling and porting the intake and exhaust ports as well as having LS1 sized valves installed. ... I thought the 2004 GTO had 243 heads My ride is a 2002 Camaro SS SLP #3296 with 30k, LTH, 3" Y ...s10xtremist Discussion starter. 7846 posts · Joined 2006. #10 · Dec 26, 2012. Iroc-10 said: They ran the yellow springs on most of the 243/799 heads, because in the end, they ran them on the GTO, and TBSS, as well as the higher HP 5.3. Looks like sodium exhaust valves are about 65 grams and the intakes are 74 grams.Mar 2, 2021 · The combustion chamber diameters can play a big role in hindering flow and performance. The 706/862 combustion chamber diameter measures out at around 3.670" and the 243/799 combustion chamber messages out at around 3.880” and giving the fact that the LM7 5.3L engine bore is 3.780" this more than likely has something to do with the power loss ...We are talking head casting numbers here. Some of the other folks can chime in and correct me if I'm wrong, but there are a few different casting numbers for the LS motors, particularly the LS1. LS1 806 Heads - 97-98 853 Heads - 99-00 241 Heads - 01-04 LS6 243 Heads - 01-04 (only 02-04 zo6 came with sodium filled intake valves) LS2Friend of mine has a set of 243 casting heads that came off of a LS2/GTO engine. I have a stock 5.3 I'm working with, with the 862 casting heads, and... in this thread in this sub-forum in the entire site. the LS6 243 heads have the hollow Intake and Sodium filledOEM GM 862 cylinder heads removed remanufactu 7477 posts · Joined 2005. #29 · Nov 2, 2013. Stock 243 heads are good for about 20 hp on a 2004 LS1 and can often be found for about $400 or so. 2004 torrid red with red interior A4 GTO (1 of 499) TR-230/236 cam/TEA ported Trick Flow 215 heads/4" CAI/100mm MAF/ported FAST 90/Kooks/Magnaflow. Pros And Cons Of Doing A 243/799 Cylinder Head Swap On The LM7, DESC The 799 and 862 heads have their own pros and cons. While the 799 heads offer better flow and performance, the 862 heads offer better combustion chamber design and improved efficiency. Ultimately, the choice depends on the specific needs and goals of the engine. Pros of Using 862 Heads. Cons of Using 862 Heads. You will see 50+rwhp probably at same ps...
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