Just to wrap up; installed the new TVX valve and drier (whew) and shot in a couple ounces of oil and 45 ounces of freon.

As the guy falling off the Empire State Bldg said "So far so good".
Temps and pressures are good, and the sight glass is actually full for the first time since I bought the car in '91. When I shut it off, the hi & low sides equalize pressures a lot sooner than before.

A couple of observations:
- TXV install was all it's said to be - avoid this if you can.
- No evidence of any crud in the old TXV however, looked clean as new.
- Cut open the old drier, absolutely dry inside, no evidence of any oil. The dessicant looked to be crumbling a bit, but no particles found in the line all the way to the TXV.
- We pulled vacuum on the new install, shut the pump down and let it sit for 10 hours - no loss of vacuum at all, maybe the system is pretty tight.

So, I guess my conclusion is still a faulty TXV valve.

Thanks for your inputs.

DG