Im buying a 05 6.0 with 317 heads out of a silverado. This is going into a 99 z28 .I am going to run a tr 230/224 cam. My question is how much can i mill the heads without having any Ptv problems. Also what head gaskets should i use .I am going to add some arp rod bolts and head studs too. I plan to run some nitrous down the road.

 

I think the most you would be able to mill those heads is about .020" before piston to valve would get questionable. If it's in your budget, I think you would be better off trying to get some 243 heads and selling these. Even with milling these .020" you would be stil be at a 69cc chamber, the 243's start at a 64cc chamber which will give much better compression.

 

Here is what i have some 853,862,and317 heads. All are stock and i would like to get ported which would be best for my setup. It will be in a 99 z28 full bolt on tr230 cam and 4000 stall. Any ideas on track times and hp numbers?

 

If it was my car I would get the 862s ported. That is a 5.3l casting head and will start with a 62cc chamber. In stock form those heads won't do so well but once ported and with some larger valves the heads work really well. We have done a lot of porting on these heads with great results. Feel free to give us a call and we can go through some option for you.