ARE YOU JOKING? your really going to pick your transmission based on your diff ratio? If you want fuel economy go with a 700R4 and gear it to that. It has a nice low first gear with an overdrive 4th gear. what tire size are you running? that makes just as much difference as anything else. what motor are you running? whats the powerband like? does it make its power down low? up high?

the shift kit is a must as well. a b&m street/strip kit will do the job