What is the seal diameter suppose to be on mark IV big block balancer? Is it the same from 427s to 454s? The reason I'm asking is I bought a new 427 GM performance balancer from PAW and a new cast front cover from Edelbrock. The seal that was installed in the new cover leaked enough to spatter the windshield before I put the hood on. I pulled the balancer and cover. When I slip the cover on balancer you can hardly feel it slide onto the seal. Small balancer? Faulty seal? Thanks, Keith