Exploding Torqueflites

sooooo....
i have a 400 with a .509 cam, edelbrock torker intake, will have 3.91s and a 3000-ish stall converter soon.....i don't know what EXACTLY the tranny is...whether old stocker, rebuilt, or what.....

guess that's bad?????

also, how good are the TCI or Mancini trannies???

i was kinda looking at the tci competition ($850) and puting a manual/auto valve body in it....
dunno bout Mancinis but TCIs reputation for 727s is junk