Chuck: Thanks very much for pointing me toward that fine essay on the transmission vacuum issues. I will have to make some of the tests he specifies to see what the vacuum numbers are for idle and full throttle conditions as far as vac to the tranny modulator. Since my car is a 1980 300 SD but has a 81 D motor and transmission ,I expect that I should be looking for a 81D engine compartment vacuum diagram. Anyone with input on that issue? I have resolved all the vacuum issues as far as heating,AC,auto locks and engine shutoff. Thanks and Happy New year to all. Willie