I have a 91 250x with an 85 350x motor in it. I am looking to possably put a high compression piston and mid range cam and of course springs, valves.I have heard horror stories of the piston smashing the valves. What is a good combination? Also is there any differance from 85 350x to 86 350x motor?

 

call powroll @ 541-923-1290.

 

I have that same conversion and added a 12:1 piston and a white bros. mid range cam. I also installed new valves and stiffer springs. I had to buy a new cam chain because the original '85 chain didn't hold out and it kept on slipping a tooth on the cam sprocket causing the valves to hit the piston. After I installed the new cam chain I haven't had any problems since.