installed z/o6 cam in my 5.7 truck now i have excessive valve train noise. i'm running a 7.400 length push rod now. someone suggested running a 7.350. i need help...

 

Shorter pushrods will only make it noisier. Comp. makes a 7.425" pushrod, but you'd be better off buying a $20.00 pushrod length checker and seeing where you end up.

 

the Z06 cam has a smaller base circle, which is why you have valvetrain noise. The LS6 engine compensated for the base circle diameter by lengthening the valves in the LS6 motor. I'd go with the 7.425" push rods, but probably wise to get the push rod length checked and make sure.