with a chevy rear, i think you can swap the 4.11 down to a 3.23 without changing the carrier. (pontiac cutoff is 3.36). i think this holds true whether you have the 8.2 or 8.5 chevy 10 or 12 bolt, but dont quote me. novas used different rearends thru the years.
4.11s use a 3 series carrier, and unless you want to change that, the gear choices are somewhat limited. 3.23's are great gears for what you're after, i think. still some low end grunt, and bring you down almost 1000rpm from where you're at on the highway.
