I have a 1966 mustang and want to up grade the rearend. I have heard that I will have a great deal of trouble because of the tapers in the axles. Is this true? What could I get a 9" out of that would be easiest to put in? Also, I have run across a 1962 Ford truck, it is a work truck with the cabinets on it. Im guessing it has a 9" in it would this work? Also it has a 4 speed in it, is this tranny stronger than the 3 speed i have in my car?