I guess I should clarify a little. If you have a stone stock Mopar then you don't need to worry about any of this. Torqueflites were made to handle less than 400hp motors and when you stray from stock thats when you run into problems. Higher HP car have the ability to break the over running clutch. Most people put shift kits in their transmissions which enable you to "hold" a gear when they up the HP of their car.
I have a good question, what happens in a fairly powerful mopar when your 1st gear (Manuel 1st valve body) burn out is really quick (street car, on street tires) and you need to shift into 2nd all the while tons of wheel spin all threw 2nd gear then going into 3rd I let off...very long black marks, my bigblock Dart was that way... 550hp according to what it felt like and it was a power house for sure a 426 wedge well built... but it did have a bolt in sprag.. no hooking anything with that car but was my Sprag in any danger?A bone stock auto does not have low band apply unless you put the shifter in the low 1 position. Then the band is on. In the drive position the band is not on.
If that is what you have then I would always make sure your low/reverse band is correctly adjusted and only do a burnout in manual low 1. I would not shift out of that gear until the wheels have come to a complete stop. Then shift to drive and make your run. But that is still not 100% safe because during your 1st gear take off your tires could slip and regrip which shocks the sprag.
You really should get a manual shift valve body with low band apply.
This would have the band on any time the shifter is in first gear and it would stay on until you pulled 2nd at which time you are off the sprag. IMHO.