Spudders when it's hot..

Do you know what cam is in there? The TC stall is gonna depend on that plus the engine internals (pistons, deck height and such), and if the cam is pretty radical, then IMHO a cam change may be in order to get the TC stall down to something more normal for street use. If the engine is a pig getting started and it got worse with a lower gearset , it is likely the cam is very big. It's just gonna get worse with a lower stall TC with the same cam.

Then there is the pistons and such......lots of questions.

I'd be figuring all that out and planning/making all those changes first. It is gonna make some big changes in tuning. Not trying to make it harder.....but starting out with a cam that needs 4+ gears and a 4200 stall TC for pure race, and moving that to a street engine, is a big change.