Based on the suggestions I got here, we did some filling and flushing of the gas in the tank. I got the fuel to be just slightly more golden than fresh gas, decided that was close enough, and put the plugs back in and reconnected the fuel line. After a bunch of cranking the engine chugged into life. It ran a little rough, seemed to smooth out, then died while running at fast idle. I started the engine several times and each time it would run a few minutes and then die. At one point it backfired a little bit through the carb when trying to restart, then started and ran. At that point I got frustrated so we quit for the day.
There a few issues that need to be addressed. The car steams out the exhaust and where the manifold attaches to the block. When I put the engine in back in the '90's, I switched manifolds because the donor engine was set-up differently. I didn't use sealer on any of the bolts or studs (some studs unscrewed from the block along with their nuts when I removed the original manifold). I later learned this was not a clever thing to do. I have some questions:
1. I'm trying to avoid pulling the manifolds off the engine if I can. Can I drain the radiator, un-do one fastener at a time, put sealer on it, then reinstall and go to the next one?
2. What sealer should I use?
3. I'm thinking that the stalling issue is carb related because the engine also stumbles when I try to give it gas (accelerator pump). How can I pin it down?
On the positive side, I'm very pleased that the engine started today. The oil guage went right up to 40 PSI and the generator is charging real well. When I think about it, the engine behaved the same way the last time I ran it back in 1998.
All ideas appreciated. Sorry for the long-winded post.