The 228-248 have the same stroke and deck height. The 270-302 have the same stroke and deck height. All use the same rods. The 248- 270 have the same bore. A 248 with a 270 crank and modern custom pistons would be a 270. Bored it could be a 292 or so. A 302 bored with a 248 crank would be about 300. Lots of combos even with stock stuff but when custom rods, and pistons come in it gets interesting. Then there are Ron Golden's Hudson rods with 1.25 lbs saved per cylinder. It's just too much fun.
