For the 3.8 L engine, 2 hours.
does a 1991 thunderbird torque converter have a drain plug
If it is a 5.0 from a 1991-93 Thunderbird/Cougar, then yes
5x7
No
it is located on the steering column
My 1991 Mustang 5.0 LX came from the factory with ( 5W-30 ) I ASSUME your Ford Thunderbird would be the same
Yes
Around $250-300 lowball should be expected, though $400 would not be out of the question (in my opinion).
Thelma and Louise
My 1991 5.0/H.O. was rated at @ 210 hp.
two one on each manifold
changing the water pump is quite involved. I recommend a manual. The BGB is expensive, but is well worth it.