You're probably thinking of a GMC 270, and no, it won't swap. The GMC engines are longer, and there's no way the crankshafts will interchange. With enough time and money, it's possible to increase the stroke on the 235 crankshaft, however. The old adage "there's no substitute for cubic inches" still holds true, so if you can find a 261 engine to hotrod, you'll be ahead of the game from the beginning. The 261 will bolt in anywhere a 235 will fit, and it's more likely to respond well to go-fast modifications. With the right bore and stroke setup, a 261 can get to almost 300 cubic inches.
Anytime you start doing major modifications on a stovebolt engine, get ready to spend some serious money! The parts aren't as plentiful or as cheap as small block V-8 stuff, and the oldtimers who know how to wring the best performance out of these old engines are getting scarce, too!
If you're near Nashville, drop me a private message, and we can talk in a little more detail.
Jerry
