TMCNo1, those were my thoughts initially. I was so unhappy with the prop I had on it I called MC to find out what the oem prop should be so I could put one on. I was stunned when they told me the 4 blade stainless was it. No body could tell me who made the prop or much about it (diameter or pitch). I had a local prop shop, Airmarine out of Chicago, tell me they thought it was done my Michigan Wheel. They also told me to guard the brass insert with my life since it can't be ordered anyplace.
Regarding the distributor, its a GM from discount inboard marine. Their part number back in 4/98 was prs44-879 and cost was 173.50.
Regarding the carb, while the engine was being rebuilt I used a holley refresh kit and rebuilt the card. It's actually an easy carb to work on. Just follow the directions in the kit. The powervalve in the kit was not the same size that was in the carb, but I used it anyway. I didn't have any hesitation issues after the rebuild, so I just continued to use the new PV even though it was different than the original. I used a vacuum gauge to tune the carb and the motor runs flawless. The electric choke is broke, but the engine warms up so fast it's not a big deal.
Most prebuilt marine BB rebuilds offered from engine rebuilders are low HP (300 ish) and a two bolt main. None of them had a short block I could drop in, so I opted to have a local shop do the work. The guy who owns the shop races boats, so he has lots of experience with marine motors. Regarding getting the 4bolt Gen IV big block, yes they are difficult to find. Not impossible, but just not real common. You'll also find that the hot rodders love the heads from that engine. I seriously thought about going to a new generation BB and heads. I don't remember the exact amount, but selling the heads would have offset a lot of the expense. As it turned out, I spent $2470 getting it rebuilt. List of services: rebore .030 over, align bore, rods reconditioned, cylinders hones, polished crank, block resurface, magnaflux block, valve job, heads refaced, magnaflux heads, cut for seals (I may have missed a few). List of parts: block, pistons (speed pro forged), rings, bearings (main, rod & cam), wrist pins, gaskets, lifters, oil pump, valve st seals, freeze plug, spring shims.
Moral of the story - remove the petcocks and put plug in so your not tempted to just open them. When you remove the plugs, poke the holes in case there is sand in there.