The 318 and 319 are essentially the same transmission with the 319 using the BW overdrive in place of the tail housing on the 318. 319's were used in car and truck applications from 55 through 65. 66-69 used a full syncro Saganaw trans (7 bolt side cover) with a BW OD. There are minor differences between the car and truck transmissions such as the indexing of the shift arms on the side cover and the lower mount bolts are threaded on the truck version. Internal gears are the same in this transmission series. There are some variations such as the mid 60's Chevelle which has different internal gears that will not interchange with the other version. They look similar externally however and will work in other vehicles.
If you need assistance with the OD install give me a call.
562-225-5869 Fred
