4.8 to ls1

[casey.shoemake]

4.8 will make about 290-315whp. LS1 will make 390-415whp. Biggest difference will be the lower rpms, and torque though. My cammed 4.8 made as much as my stock Ls1 does. edit Another option for you is to get your 4.8 heads ported and polished. Some places do that for around $500. Out flow the 243's and have a smaller CC chamber.

Were talking about pp the 862s rite? Wow, always thought the 799/243 were the next best thing to l92 heads. I wonder what the compression would be like with the smaller chambers of the 862s?

[ff_jeff]

Were talking about pp the 862s rite? Wow, always thought the 799/243 were the next best thing to l92 heads. I wonder what the compression would be like with the smaller chambers of the 862s?

here LS1 Info and Specifications - SMOKEmUP.com
the stock 243 heads are nice. But many people use the 5.3/4.8 heads and port them. If you have a set, and jus pay for machine work, you dont have to buy the $500 243 heads, then machine them. at 61cc stock, you can even mill a little more off. 243 heads are 64.4 cc.
a ported 243 should out flow a ported 5.3, but you will pay for it. Check out prc heads, tx speed heads ect. They all sell ported 5.3 heads. I think their 5.3 flow like 300 at .600 lift.
with 61 cc heads, and a stock head gasket thickness (.051) you should be at around 10.75 CR. or so. With a .041 gasket right at 11.0cr.