Originally Posted by ricford
I don't think it's a matter of Indmar vs. PCM. The LT1 engine is built that way, and if I'm not mistaken it's the only one. The belt drives the alternator and the raw water pump, the circulating pump is on the cam. Hope you didn't overheat, because you had no raw water pump when you broke the belt.
It only drives the alternator on the LT1, no fear of overheating. However, without an alternator you can't really overheat anyway.