Originally Posted by junior stocker
I think the biggest problem here will be finding a "dedicated" gasket for the 283. Virtually NO ONE makes them in under a 4 inch bore, unless you go with the racing/specialty aftermarket ($$$$). I just got lucky, and found a NOS complete gasket set for a 283, including steel shim head gaskets. Butch/junior stocker.
Mertz has bored the block +0.030", so the new bore is 3.905". At the very top of the bore, the machine shop would have cut a chamfer to ease entry of the rings into the bore. I have no idea what the O.D. of that chamfer is, but a WAG might be 3.930". That'll leave 0.035" difference between the gasket and the bore on the radius. Close enough in my opinion.