I bought a really old boat in great shape. or so it seemed. I found out why it had been parked. the gimbal bearing is out of it. well the original owner sold it and the next guy tuned it up and got it running again to find out the bearing was bad, and parked it again. well this time it was'nt drained and winterized. the block is cracked. runs like a dream ortherwise. It has a 230 (150 h.p.) g.m. inline 6-cylinder engine in it. I found a 230, and a 250 in a junkyard. I looked into it and found the only difference in the 2 is the stroke. meaning the crank, and the piston wrist pin locations are the different. I want to put the 250 crankcase with my head, and other externals in it. since the crank is stroked different I was wandering what the consequences of using the production truck crank and pistons and stuff would be. What if it's a cast crank? I'm not sure, but i think they would use steel cranks. I know the heads have stainless valves and hardened seats. but, what's the difference in the lower ends??