You want the 95 and newer models. They have a 5.61 1st gear and a 3.04 2nd gear. Earlier versions had 6.34 1st and 3.44 2nd.
I have a 4500 in my 2wd Burb turbo diesel with 3.73 gears and 265/75r16 tires. I don't even use 1st gear unless I'm pulling a trailer.
I'd thing a 410 ratio would be good...