I use the Comp EDM lifters which are not tool steel. My cam was nitrided and I broke it in on just the outer springs. My pressures are like 140 on seat about 350 open. Been running that setup in my 63 over 8 years since June 2011 and it still runs the same 10.70's and 10.80's. Ron

Last edited by 383man; 11/10/19 01:46 AM.