Originally Posted by csk
if raising the intake roof be careful where the cut for the spring pocket is, not sure on your heads but most are very thin there, ask me how I know LOL

What is sufficient thickness to leave here?

I'm running the CompCams beehive springs, part# 26056, 400 lbs./in. rate, 1.100" Coil Bind Height, 160 lbs@1.800", 420 lbs@1.150". Can't imagine going to a much higher pressure than maybe 550-600 lbs in this street application.

I should be able to gauge the thickness with either my ultrasonic tester.