A T6 turbo frame is about 12X10, as big as a car battery! Also the LS guys running that turbo are using a head that flows 240ish out of the box, >280@.500 ported... with the 318 (302) head flowing ~172@.500. Sell it for $$$ and get a smaller $$ matched size. I dont think a 4sp would benefit a turbo, youll never get it to spool in that low first. They like to push on something, like a shorter rear gear. 1:1 final is the same in both trans.