390 with a 5 speed (not ordinary)

[67GTSCode]

Ok here is the deal.. I have a 1967 Mustang GT coupe that is an s-code ( only 1546 of these were ever made ) since it is an s-code that means that it HAD a 390 in it.. ( it currently has a 320 + hp 302 in it) NEWays, I am wanting to put a 5-speed behind it for gas milage and a better topspeed, however i am planning on putting a 390 back into the car ( the 390 will deffinately be hot ) what i want to know is if the 5-speed will still fit and be ale to handle the torque.. becuase i am on a tight budget being only 16, i want speed but i also want looks and i don't want to waste money on the tranny if it wont work when i can put in a new interior (cloth) .. I am reading how 5-speeds can cost from 1299 to 2100 i was also looking at a T5 from 5.0 mustangs to put in ... only $600 and i can get the gears for cheap. will a t5 handle it? or will a 5-spped even work

any help appreciated