Dear Josh;
Don't try to "re-invent the wheel" here.
A 4X4 has low gears purposly. It's for climbing around in the desert sand/snow and not driving down the highways 70+. Also; There's a special relationship between the front drive section and the rear. The rear can't push any harder than the front pulls etc.
Gearhead is correct in that a 261 will produce more 'low end' which a 4X4 needs.
You can put OD behind your 270/302 for fun on the road.
