What Next? Headers or 3.73's?
I did LT's before the torque converter.....I'd do it opposite if I could do it again. I like the sound of my exhaust, but I love the way the car pulls with the TC. From a stop, from a roll, low speed, high speed....it rocks everywhere. TC, TC, TC!!! (Even though it wasn't one of your choices.)
go with headers. long tubes.... 
remember, you need to match your stall with all your other mods. might be best to call a place like TCI or vigilante and have them help you decide, i think one may even make you a custom one. a 3600stall and a set of 3.42 gears would be really nasty IMO 
