[Oldsguy]

Yes but the deck heigth on a big block is like 4.2 inches and on a small block is like 3.3 inches, there is no way you can shave that much so you can't interchange the intakes from big block to small block. The heads are the same outer dimensions so valve covers will interchange and castings are similar except for actual size of the cylinder diameters. In fact, was just reading about a reference to the 403 on another thread and it's bore is greater than the 455 but it is considered a small block because the stroke is the same as the other small blocks. I think I read someplace on R.O.P. that someone actually bored and stroked a small block to greater total discplacement than a 455 but that was really radical, he used some chevy big block rods for instance. I am not a machinist so this stuff is beyond me.