Maybe the cam or lifter brand/type is a more universal issue, possible preload or even oil weight etc. With 55+ year old blocks making more power than factory it's also a possible metal fatigue issue etc.
Glad there's 2 aftermarket blocks that are fairly priced.
__________________
69 GTO Convertible, 4000lbs
462ci, 606tq/569hp - 93 oct @ 34 deg (207psi)
11.7:1, KRE H Ports, Lunati HR 282/290 w Johnson Lifters & 1.65 Scorp, E30, EFI, Holley HP + Dual Sync, 12-1 Crank Trig, 120lb Inj & 1000cfm TB, Torker II EFI Int & Rails, PTC 10", Rock Valley SS Tank, Dual 450s, Aerom EFI Reg, Aero Front & Wilwood Rear Disc Brakes, Dougs 1 7/8" & Borla Pro XS 3", Alum Rad & Dual Fans, 12:1 Box, UMI Arms & Viking Berz Fr + Rear CO Shocks, Hella UP5.0 Vac Pump, 12 Bolt, 3.73, 33 Spline
|