<<< C4 Corvette owner, converted OptiSpark to a DelTeq Northstar-based coil system. The problem with LT1's from this point forward to eternity is that the aftermarket support isn't there (specialized parts from SBC and LSx, very expensive) so for the HP or reliability/ease-of-maintenance, an LSx will remain a superior choice.
Price out a good longblock refresh on an LT1 (waterpump, new serpentine belt/tensioners or even a custom accessory system for the 944, OptSpark or ignition conversion system, new gaskets, etc) and then see if an LSx isn't still a better option.
The ONLY thing in my mind that makes an LT1 somewhat attractive from a swap standpoint is if you never plan on modding it for power. 300hp is what you can reliably expect, whereas an LSx is cheaper/easier to tweak to 350hp+.