Weird sounds? when I tap the gas.

Weird squeeking sounds after getting new gears.

I just got my car back last night. everything sounded fine. when i started taking off not going to fast. but just usual acceleration. i hear a squeeking noise.i just got 3.73 gears put in the rearend. the breaks squeeked before only when i would go to stop. now it does it whenever i press the gas. this is really weird. what would make this happen. anyone please help. also i upgraded from a 28 spline diff to a 31 spline diff. and got new 31 spline axles too. it is a 96 cobra. please help it is really pissing me off. wtf