I am nearly done with the home port job on my heads and will be taking them to the machine shop soon. I was originally going to have .030" milled off to yield a 10.0:1 CR but now I am thinking I want to go more, like 10.5:1. The cam I will be installing with them is a FMS 214/216 .535/.545 113+4. What is the most I can mill them without PV clearance issues and how much needs to be milled for a 10.5:1 CR?

 

I had mine milled .050 to get the 10.3:1. I've heard of guys going as far as .070, but to me thats just too much. If you mill them more than .030 you will need some 7.35 pushrods also.

BTW, with my heads we had to port the intake some to get the runners to line up all the way with no restrictions. Easy to do with a dremil and sand paper drums.

Hope this helps some.

 

What head gaskets were you using? I already have a set of stock graphite gaskets so they will be a little thicker.
I have been reading and it seems if you mill enough to make you intake not line up right, all you have to do it take a little off the alighnment pegs on the intake to get it to seat right.

 

Snake... what lift cam were you running with the .050 milled heads?

 

What about for boosted apps... I wanna S/C my 5.3 and I was wondering if I should do headwork and have them milled, and if I should how much?

 

If you are going boosted, you definately do not want to mill the heads. This would increase compression ratio, which is bad for FI. Most of us FI guys drool over ported and polished 6.0 heads. You want to lower your CI for FI, not the other way around.

 

Good to know... So I should go with some 6.0 or LS1/6 heads and have them P&P?

 

Stock 6.0 heads flow less than stock ls1 and ls6 heads.

P&P 6.0 heads flow better than P&P ls1 and ls6 heads.