Been there done that. Fitted GQs to a 1990 rangie. Most stupid thing I did. Spent 1k on a custom dc rear shaft and still had massive vibes. Brakes were no better as well. Ended up putting in an 80 series rear. Still drove like crap. Doing things properly with my current rangie with stronger axles instead of diff change. I will be running 35's fine and still drive nicely how a rangie should:-)
Good luck with it... I wish I never did it to my old rangie though.
Camo

