Truck & mods are in my sig. When I had my gears installed this past Friday, I had the guy measure my pinion angle. He said it is 8-10* up.
I feel a vibration on WOT or on a load, like going up hill. It is usually at slow speeds, up to 20MPH and around 65-75MPH.

Should I just get a set of 6 degree shims & call it a day, or should I get a set of 6 degree & 2 degree shims & stack them?

 

I.... wouldn't stack them...

Go with the 6*

When I was at 4/6 I believe I had 4* shims...and needed a bit more to be good. So 6* should be good.

 

mine was like 6.5 up. i did a 6 degree shim and it appears factory. i havent re checked it because i forgot angle finder at house when i did it. but zero vibrations. and rear end has a positive feel now when leaving from stop. cant explain it. you just have to go from a messed up angle back to a good one to understand it lol.

i bought procomp 6 degree shim for 2.5 inch leafs on summit shipped for 18 bucks