Like an idiot, I didn't check the angle before I put 2 inch blocks in the rear. I now have a vibration at low speed.
Will a quarter inch shim get me close to the correct angle?

My truck is a rwd super crew. I'm afraid the vibration is putting too much stress on the drive line. Thanks in advance!

 

Update, I switched the location of the factory shims from the top of the lift blocks to the axle plate and all vibration is gone. I read about where, and found conflicting information, this may save someone some trouble and time if you install blocks.