gslse vs gsl differential?
 

Ive heard they are different. is this true and if so, how are they different?

SE one is heavier, I know that.

GSL= 3.91 gear
GSL-SE = 4.10 gear

The '84-85 GSL and GSL-SE is the same other than the gear ratio. The '81-83 GSL used smaller axels, and had some other variations that were upgraded in the '84-85 modles.

Okay, so you're close. The SE has one less clutch than the GSL unit to make room for the offset of the pinion (slight) with the bigger ring gear. GSL has slightly taller gearing and a little more bite. I put my GSL diff back in my axle when I swapped the SE axle in.