RE: Evolution 58GX - what RPM's should it turn?
Pretty hard to blow out a gasket with the 5 or 6 lbs pressure in the case...Maybe the surfaces are not exactly flat ? Or the gasket material is too thick and compresses at the corners ?
Sounds like the old 3W problem with the phenolic carb insulator block, tighten the corners too tight and the block warped and leaked in the center...
Just for a reference, the base gasket on a G62 is about 1/8" wide at the thinnest part, on both sides at the transfer ports...The cylinder bolts are about 2 1/8" apart...Can't say as I ever saw a blown base gasket on a G62...The factory tightens the cylinder bolts so tight they come loose with an audiable "pop" .....[8D]