what's the best posi unit i can get? which one has the most bang for the buck? my ranger is not a daily drive, but it's more then a weekend toy. i know i don't want a spoil or a mine spoil. and i want something more then a stock limited slip differential. i'm planning to put a 302 in it (300 to 320 hp) and put 34s to 37s under it. i know it will push the 7.5 rear to it's limits. but i have seen 80s mustang in the 12s with a 7.5 rear, so i know it can handle some hp. so what would your suggestion be?