Z28 Boy

i have done a lot of looking around, and it sounds like the reccomended method for breaking in a new rear end is by driving it softly for ~10 miles, and letting it cool for 30 minutes. repeat a couple times, and change the fluid. possibly, also changing the fluid after a total of 500 miles.

question 1: i plan on using Amsoil synthetic once it is broken in, but should i use non-synthetic to break it it? i know with my new motor, everyone said to break it in with the dino oil, and THEN switch to the good stuff.

question 2: i remember somewhere reading that it is better to break in the gears without driving the car (i.e. let it idle in gear on jack stands). the same plan from above would be applied. the idea here was to allow the gears to go through a number of heating cycles while not under a lot of stress. anyone ever hear of this?

background info: '91 Camaro with a 7-5/8" 10-bolt with a take-off differential from SLP and the Motive 3.73s that SLP sells. in case you don't know, that differential originally came on the Camaro and Firebird prior to SLP making them into the SS, WS6, and Firehawk. (so, it's basically a stock 4th-gen differential)

i want to make sure i get these bad boys broken in correctly - any and all help would be greatly appreciated! thanks,

-brian