[mr0077]

I'm with Ernie, I Love my 3.31 rear gear and close ratio...torque is NO PROBLEM, and 25-30 mph shift from 1-2 is very comfortable...speeds in gears at 3000 rpm for a close ratio with 3.31 rear gears is 31 in first, 43 in second, 56 in third...but you said you're reaching for 4th at 60 right now with the 3.50 gears, so that won't change much...
I think 3.07 or so would be a little to tall for a close ratio, but would likely work with a wide ratio...