well you have 3 options , the Tremec 5 spd od , the Keisler 18 spline hemi OD or the factory 833 OD , the keisler & the factory are basically a bolt in deal , the tremec is a bunch of modifing & it is really no where near as strong as the 833 version .the other consideation is the gearvendor that bolts onto the rear of the 833 4 spd , it is probably the strongest way to go & will give you 5 speeds