I am new to Mopar with a 1973 Dodge Dart Swinger. Curious on what the best rear end would be. I dont want to spend a ton of money. But what I am looking for is a posi rear end with gears that would be snappy out of the whole but still allow me to cruise at 75 with out pushing the revs to high. I am running 18x8 in the rear with a 45 series tire. Also, wat would be a good tranny with my current 318 and possible bump up to a 360 later, wanting atleast 4 gears possibly 5. Any suggestions? Thanks!