Quote: What about the question about timing, what is the initial, total without vacuum, and total with vacuum advance?
Item 1, see above.
Item 2, Do not overlook a restricted exhaust. make sure the heat riser is wide open, then disconnect everything from the head pipe back. Pretty simple and will eliminate it.
Item 3, The pulley sizing is also a possibility if the truck has been messed with over the years.
Item 4, Possible but unlikely. you appear to have a borderline heat transfer situation. Disconnecting the trans will most likely improve it due to removing a heat source which is designed to be there. That may mislead you to believe the trans is the culprit when you are just chasing your tail.
Keep it simple and 1 step at a time. Try to repeat your testing as EXACLTY as possible.
I will add that I use a digital thermocouple meter with a probe into the system as close to the thermostat as possible. doing so Gives you an EXACT readout if how fast and when things are changing
