blsnelling

iTrader: (4)

I'm looking to install a set of 243/799 heads on my 5.3. The stock heads have a combustion chamber volume of 61.15cc, and 243/799 heads have a volume of 64.45cc. My stock compression ratio is 9.5:1.

I already know that I need to mill the heads .007" to lose 1cc of volume. Just to get to stock, I need to mill .023". Let's suppose that I want 10.25:1 or 10.5:1. What size combustion chamber do I need?

What compression is conservatively safe for premium pump gas? I want to take advantage of the opportunity for a little more compression, but don't want to live on the edge either.a

blsnelling

iTrader: (4)

Surely someone knows.

Coban

iTrader: (14)

You can use a compression ratio calculator online and work backwards. That's what I would do. You might have to use a guess and check method. 10.5:1 will very likely require premium but it really depends on the cam you use and your resulting dynamic compression ratio.