80's A998/A999 into Early A

70DartMike said

The only place it isn't leaking from is the pan. Basically, fill up the tranny, drive for however long, no leaks. Don't drive the car for a week, entire amount of tranny fluid ends up on the ground. I'm sick of replacing seals and still having this problem.
I also remember the 80's tranny behind the 318 having what seemed like a taller ratio? I'm trying to get the best fuel mileage I can since I daily drive the car.

Click to expand...

all 904 transmissions have the same 1 to 1 high gear ratio so the 80's tranny isn't going to affect hwy cruise rpms or fuel mileage. But it may have the low 1st gear set so it could help take off. In the 80's Mopar used some really tall gear ratios in the rearend. That's why it cruised at such a low rpm compared to your Dart

BTW: the leak your describing is called a static leak. Two of the most common problem areas that cause a static leak is the o-ring seal on the dipstick tube and the shift shaft seal.