[vegetto]

i've got a 1977 dodge d150 with a 3speed auto, and i'll be pulling the engine and transmission out this winter. while its all out, i was curious if anyone has put in a 4 speed instead? don't know what all it entails, just thinking about it for now. i'd like to get a little better fuel mileage when towing things on the highway.

 

[dana44]

You can do it pretty easily. Get an early one before 1996 (I think) and companies like TransGo have the necessary switches to engage the overdrive unit. Pretty simple, a nice upgrade for any early truck.

 

[valiant67]

The big change is the trans crossmember. The 4 speed auto is bigger but the truck should likely have plenty of room in the tunnel for the new trans. Dana is right, look for a pre-1996 donor.