Gears don't match
 

I have a 1994 f150 4.9 liter 4x4 manual 5 spd. gears don't match up while in four wheel drive brother I got truck from re done rear axle out of a e150 van or two wheel drive what is supposed to be the right gear ratio for it so I can buy the right stuff to fix back to stock I live in the snow and use four wheel a lot I know it's not good for it the way it is any help would be greatly appreciated the invite to keep her alive

Do some homework and find gear ratios you have now. Find matching to front in wrecking yard and change the rear axle out. Other option is to swap rear gears.