bolt the head onto the bare block and reach your arm up in where the piston would be and scribe the outline of the bore onto the cylinder head cody
I always put the head gasket on the block and see how much difference there is between the cylinder and the gasket. Then put the gasket on the head and scribe a line on the head.
I agree with the above. For a 455, you can unshroud to the limit of the bore or the gasket, whichever is smaller. By the way, I can't imagine anyone is running the bore larger than the gasket, are they? For a 400 or 430 you don't want to be limited by bore diameter, though. Here's a chamber from my original '67 430 big port heads, converted to Stage 1 valve sizes and unshrouded to about 4.33", done some time in the late 1980's. This is larger than the bore on a 0.030" over 430, so I notched the top of the cylinders to help out. You can see the mark left on the head surface by the steel ring on the inner gasket surface. Devon
I have always scribed the cylinder bore, not the gasket. Of course, for this you need an empty block.
There is only one problem with that picture! You should of ground the cut flat in the chamber area, You just created more turbulence with that left there, Grinding that flat will give you another 5 to 10 HP. Remember do both side's not just one. Good luck Gary
