Thanks for the replies. I'll take a look at PowerSource. I will be doing the labor, so that should save a few bones.
As for the crankshaft, the sources I've seen list the crank casting # as the same from 92 through 94 - #747. I'm not certain that means the crank is identical, but I believe it does.
The heads may even be interchangible from 92~94. The head casting for 1992 is #619, while the head casting for 93~94 is #2163. One remanufacturer lists both numbers for 1992, the first being #619, followed by #2163, separated by a semi-colon, as if to indicate that #2163 is an alternate # that is interchangible. I'm not sure, though, it could be an error.
At any rate, it would seem, at the least, swapping a 93 ECM would be required, if not the wiring harness (provided the EGR lead isn't just going unutilized on the 92). A lot of trouble for such a small benefit.
One last question. While I would have all that stuff taken down from the old engine, and the 'naked' long block highly accessible, is there anything else I could do to reduce the risk of these heat-related exhaust valve and manifold failures?
Many cylinder head rebuilders do reasonable custom requests like porting, polishing, using higher grade (more heat resistant) valves and stem seals, oversized valves, widening coolant passages, etc.. If there would be any benefit to this kind of thing, I might consider the extra cost.
The 180' stat and trans cooler will be on my list.