I have a 71 Swinger, installing a 408 stroker 500HP/525TQ, TF 727, 8.75 rear / 3.55 suregrip, 28" tall tire. The car will be street driven including some highway trips.
I was thinking 3800 stall, what do you think is best?
You would be best to call a Converter builder give them the exact specs of your engine/car and have one built specifically for you. I have same set up as you pretty much. I called Lenny at Ultimate Converter and he built me a street strip 9.5" converter. It stalls with foot brake to right around 3800rpm, Transbrake he said it will stall more. I also have a 200 Hit of NOS on mine so the stall will most likely flash in the 4500 or so range with T Brake and NOS Hit out of the hole.
I drive my car everywhere and have put up to 300 miles on it in only stopping for fuel. You would not know there is a converter in it until you smash the go pedal. Very Docile. Solid Roller Cam & Spool too! Everything that they say you should not do on the street I am doing with success! Lol