my 383 in my vega is all stock on bottom end and a set of alum factory 1.94 vette heads with no work done to them and keith black pistons ... i have 31x14.5 and 456 gears with a glide turning 6900 to 7k in the 1/4 :wink: i cringe everytime i run but she not showing any signs of failure.... still got almost 80 psi of oil pressure