Well, I just found out that my motor mounts, which were alleged to
have been replaced during my engine overhaul, were not, and all the
mounts and vibration dampeners are completely shot, the engine is
sitting right on the frame, which is why I could never get the engine
to stop shaking the car. Additionally, the vaccum modulator on the
trans was never adjusted after the rebuild, which accounts for my
slipping transmission shifting.
Also confirmed that the a/c compressor was never installed
(lubricated) properly during the R134a conversion, which is why I only
got 19 miles out of the new compressor.