OME Lift Question: are the drive line spacer and driver side strut spacers necessary?

So I just picked up my kit from OME and I see that's the kit includes a driveline spacer and a strut spacer for the driver's side, which I'm assuming is for the "taco lean." How necessary are these two parts? I've heard conflicting stories as to whether or not these parts are vital. I've heard some people swearing that you need the spacers to get rid of the vibes, and the I see people selling them in the market place because they don't need them. Can anyone give me any info on this?

 

lean spacer for drive side strut is going to be definietly needed.

Stock the driver side spring is a smidge longer / stiffer to level the truck, your OME springs are the same and not side specific. Put the spacer in for the strut. Driveline, just do the lift then see if you have vibes and pop the spacer in and go from there, the spacer height for the CB is ALOT of trial and error.

 

Good deal, thanks for the input!