I am happy that you took time to give me a boost. I am like I said going with 71 340 pistons, stock exhust intake and thermoquad, What would you suggest for a cam and who would make it? I have heard bad things about Comp Cams from Mopar and Ford as I have a 66 Mustang too. I would like to run 355 gears or 391's I done my last 1/4 mile racing 30 years ago. Any help would be great oh one other thing I know you said stay with my 73 340 heads but another set of X heads has come my way with no valves or springs Bare is the word. I can buy for 450 + shipping. What do you think again Thanks ahead of time John.