Last night I finally pulled the old engine. No issues other than how much grease there is to clean up...
I think a lot of my oil loss was through the crankcase vent on the back of the engine. Something unique to those older small blocks. I'll have to use a newer style alternator to fit the new brackets. I was hoping I could use the old one since I know it's good and fairly new and the wiring is good. The newer alternator takes a different wire plug.
Next I'll be doing clean up and replacing my leaky heater core and swapping the torque convertor. Then I'll be ready to drop the new engine in. Maybe this weekend yet, but who knows. I've got a porch to keep building on also.
Have a great weekend everyone!