Does anyone know what is involved in swapping a A43D overdrive trans out of a 81 2x4 truck into my 1979 Celica GT Liftback. I currently have the stock 20R and A40 3 speed auto trans, and it spins about 4 grand at 70 MPH. The best milage I've gotten out of this car is 22 MPG, but it averages around 18 MPG. I read that the 5 speed versions got 34 MPG, if I could get 30 I think the swap is worth it.