my diesel has 4.11 gears in it with a 4 speed automatic and 33" tires. it does 83 MPH at 2500 RPM.. which is as fast as I am willing to spin the cummins.
I think your little truck could use 4.56's with the gas engine. This would also help you compression brake down hills so you don't overheat the tiny brakes on the truck quite as fast.
now for the manditory lecture...every year I have to replace the enormous brake pads on my truck and I have gone through 3 sets of rotors on the front Dana-60 in the past 4 years. these brakes are easily twice the size of the dakota stuff.
It's not what you have. It's what you do with what you have