Quick recap of my recent engine saga:
I tore into the 350 from the donor truck to replace bearings, rings and all gaskets. When I pulled apart the bottom end, however, I found two spun main bearings and a spun rod bearing. Needless to say, the engine had a loss of oil pressure at some point. Pretty frustrating when the engine supposedly came from a running vehicle.
I took the bottom end to the local machine shop for an evaluation. The prognosis: it can be fixed, but unless I was having a high performance engine built, it wouldn't be cost effective for them to even touch it, I was better off finding another engine.
I shopped around on craigslist for another engine and found several, but I was gun-shy about an engine I couldn't hear run. I then started shopping for reman engines and settled on a reman L31 from the local parts store. It was pricey (more than I planned to spend anyway), but came with a 3-year unlimited mileage warranty. I was also able to sell the Vortec heads and return $300 worth of parts and gaskets that I was going to put into the other engine, and basically the complete engine came out cheaper than a reman short-block would have with the pile of parts I had bought.
For those of you who don't know, the L31 is the factory engine that vortec heads came on. It came in 96-2000 GM trucks and SUVs, and is based on the post-86 GM block with a 1-piece rear main seal. This engine will bolt up to the SM465, but it uses a different flywheel (a new flywheel wasn't much more than having one resurfaced). It has a factory roller cam, which means I won't have to use high-zinc oil. The only other caveat is there is no provision for a mechanical fuel pump at all - not an issue since I am going with EFI. Also, the factory roller cams require a different distributor drive gear, but otherwise the old-style HEI works just fine.