Ok, I'm new to this mopar thing, I was a hardcore chevy guy for years, so I have some parts left over. In a recent lapse in judgement I sold my 8 3/4 because I was never going to build it, and I had an 8 1/4 with gears and a posi ready to roll, the 8.25 disappeared from a friends shop so it's back to the drawing board. I have a 10 bolt chevy II rear end that has a spool and 4.56 gear, it's roughly 57 3/4" wide roughly 1" wider (on each side) than my 7 1/4. I also have an S10 rear end that's roughly 54 1/4" which is roughly 1" narrower on each side. I've got a Mancini spring relo kit that will be used on whatever goes in. My question is would it be better to use the wider one or the narrower one? Please keep the flaming to a minimum, I don't care about bolt patterns or brand loyalty, I just want to go very fast in a very short amount of time, the rate of acceleration is the only concern. All my measurements are from wheel mounting surface to wheel mounting surface.