I've been searching arround and haven't been able to find any direct answers to my questions so I'm going to post them up. I'm going to mill my stock 1998 806 casting heads .030-.040. I'm still trying to decide if I can go .040. They will also be ported so the questions are:

1st question:
I have a TR 230/224 .575/.563 111 LSA cam and 7.4 chromoly hardened pushrods. Do I need shorter pushrods or does the smaller base circle of this cam make up for the difference when I mill the heads?

2nd question:
Can I mill the heads .040 without any problems with PV clearance?

3rd question:
if anyone knows, what will the CC of the chamber be milling .030-.040 off of the heads and what CR will it be at?

Like I said I searched many forums for this info and the only thing I could find were people milling aftermarket heads wich doesn't do me any good. Any help would be appriciated!

 

Ttt..........................

 

Instead of milling your existing heads (which are not very desirable castings), why don't you just get a set of 5.3's, take em to a machine shop and have your existing valves installed (you'll need to have the seats cut). By doing that, you get a much more disirable casting (much better combustion chambers, and room for aftermarket rockers if you decide later), and you still up your compression ratio. You can pick up stock 5.3L heads on Ebay all the time. Just my .02

 

From what I have read from this thread....
https://ls1tech.com/forums/advanced-engineering-tech/111207-ls1-head-combustion-chamber-cc-volume-vs-cr.html

a cut of .007 will decrease your chamber size by 1cc. So a .028 mill will remove approx. 4cc's. You might wanna go a little more to allow for the gasket.