This may be going somewhere...

Blue, what cam were you running? One difference with this motor VS the old 235 is the cam. This HEI worked fine with the Clifford 260M cam in the old motor, but has showed this failure mode with the M4F in my new motor.

Could the cam drive gear be ground wrong on the M4F cam?

What takes the end-play with the stock distributor? Is it the distributor body, or is the gear supposed to contact the oil pump at all??

What is that plastic washer in my Fel-Pro kit for???

thanks

chip

Preaching the Hot Rod Gospel according to the 4-stroke apostles:

Suck, Squish, Fire and Fumes