I have the 350/290 crate in my 85 right now.I want more power !! There are a few things currently done to it; like Heddmann headers and y- pipe, RPM Air Gap Manifold,Holley 650 carb, high flow Summit water pump...but more fun is what is on my bench in the shop . A set of Patriot Freedom series heads, and all the upgraded components to go with it from Comp like 1.6 roller tipped rockers, double roller timing chain and of course the new cam. BUT The sales guy at Comp actually sold me a "smaller" cam than what is currently in my motor ! I bought the 268H , but am looking at the 268 XE OR their Thumper. I need input from anyone running a setup w/ the heads I have ! Can I run the Thumper without piston-to-valve problems ?!