WebMar 8, 2024 · 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 rpm. WebApr 20, 2024 · The 706 & 862 heads have a 61cc combustion chamber. Most of the other LS cylinder heads have larger combustion chambers. You’ll lower the compression ratio if you go to some other heads. That Castech heads are the ones that are known to be the problematic heads prone to cracking..
LM7 5.3L Engine Upgrade Guide: Expert Advice for LM7
WebDescription: CNC Ported LM4/LM7 706/862 Cyl Heads .650 Springs 2.00/1.57 Valves PAIR. This Cylinder Head has a core charge of $200.00 included in the cost. This charge is … WebMar 11, 2024 · The 862's have the same port size and runner volume, they were just choked by the intake valve. Open it up to the same size as the 241's and you should see an improvement across the board. Also, the 862's have a much smaller combustion chamber volume at only 61.15 cc, around 6 cc smaller than the 241. buffest kpop idol
862 Heads - All you need to know - Auto Care
WebApr 15, 2024 · 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. WebJun 8, 2016 · Location: Raleigh, NC. Re: LS 862 head porting. by nobody special » Wed Jun 08, 2016 1:45 pm. The 317 heads basically have the 243/799 ports but with a 70cc combustion chamber. Going to the smaller chamber for increased compression is worth some power. The 317 replacement costs seem to range from $150-$300 per pair. crockett street fredericton