I have a 90' Suburban 4x4 with a a recently blown out 10-bolt axle in it with 3.42 gears. I dont have a lot of money, but I found a 12-bolt w/ 3.08 gears for a $100. I am planning on putting that in very soon. I figured I would only use the 4wd when I get stuck. Is this bad to change the gears like that, will it blow out my tranny. I am planning 3/4 axles for the summer of 2003, I just need something to move my truck.