Hello! I cant find much info on this. I want to keep my stock 87 D50 front and rear end. I have no clue what my axel sizes are, what power they can withstand, or what gears can fit them. I know I have a 3.91 ratio, which with my NSG370 and 325/75/15 tires, puts my RPM higher than I like.

I would like to put my truck at 1700-1900 with the tires that are on it.

What gears fit? What power will my axels hold? And what size are my axels?

-Paul