I've loosened the 2 big bolts the spacers are supposed to sit on top of. The differential doesn't seem to have dropped, are there any more bolts holding it in place?

No...just the two for the front diff mounts.

They don't usually drop freely because the rear bolt is tight, I had to pry mine down to fit the spacers.

did you just loosen it? or remove the whole bolt? youre supposed to remove the nut, pull the bolt completely, then it should drop. Ensure youve got a method of support like a floor jack. Slip in the spacers, put in new bolts, and torque er down...

I got the bolts off but you have to really pry the differential down to get the spacers in there and when you do, you are now trying to put a long bolt through somewhat of angle...is this right?

Yup, the bolts go through at an angle, sonoransteel has a tapered spacer, but the bolts are still at an angle.

http://www.sonoransteel.com/store_ta...diff_drop.html