Ran in a 408" for just under 4K miles. We are boring out and stepping up to a larger solid roller cam. Custom grind Comp Cams 234/242 .612"/ .592" on 115+1 Turbo Cam. LXL lobe on the intake and Xtreme RPM lobe on the exhaust. Both of these lobes are easy on springs and quite on the Valve train. This is a 3 bolt cam

275 takes it