There are at least 4 different 250 PS bracket sets for the 250! the parts do NOT play nice with each other outside their own set. I do not know about the 194/230s, but that introduces MORE possibilities. The 292 never used the "one piece" head so that rules out one set. Since the upper bracket bolts to the head and manifold spacing is the same between the 250 and 292, one of the early two piece upper brackets will probably work depending on your crank pulley grooves. The alternator bracket will ALWAYS be the same, so don't worry about that. You will have to make the rear support because of the 2" height difference. For a company famous for parts interchangeability, Chevrolet sure blew it on these brackets. My conclusion is that IF you have the correct crank pulley, one of the early sets will PROBABLY bolt on, except for the rear support. I think I still have pictures of SOME of the variations for the 250. I just went through this on my '69 C-20 Panel Truck, so it is still pretty fresh in my mind.
best wishes,
Les
