gochappy,
no parts, but you'll be just as happy running a small block chevy as you are with the olds, if your boat is a 18 footer, give or take a few inches. Any bigger, like a mini cruiser and you'll want the grunt of a big block.
We sold a bunch of 18 bubbledecks at Advantage with the sbc/berk combo (e pumps no less) and they'd run low 60s all day long with the stock engine. Plus, when you go to rebuild the sbc, it'll cost you a 1/3 of what the olds will.
I like the olds, don't get me wrong, but for an everyday fun boat that you only want to ski and dick around in, smart choice with the chebbie.
Jethro over on the banderlog board runs a sbc in his boat, or one of his many, and I think he runs about 63-63 mph.