Rear Lift Blocks

[JON BAILEY]

OK...  So I think I got my UCA issue figured out, so now onto the next issue.  I leveled my 2014 GMC Sierra 1500 with Bilstein 6112 and added 5100 in the rear.  Perfectly level, but I haul a bit and would like to get a bit of the rack back so I am not riding nose high when hauling.  I have read just about every forum post out their on flat vs. tapered lift blocks.  I would like to go with 2 - 2.25 block in the rear.

 

Flat vs tapered.  It makes total sense to me to use flat blocks to keep the pinion angles the same.  I have read many threads about how folks are getting a vibration when using tapered.  So I have been looking for flat blocks everywhere.  I have ordered superlift, readylift, mammouth, bison, etc...  all claiming to be flat, but all coming with a 1/4" taper.  I want to do this right and not have to redo it if I get the vibration.

 

Do FLAT rear lift blocks exist for a 2014 GMC Sierra 1500??  If so where???  What manufacturer.  I know I can leave it as is and live with it, but if I could find some flat blocks I would really like to try it.  So I am asking for your help!!!

 

Jonny B.

[MikeBMW]

If you tow a lot, to raise the rear about 1.5", go with a spring lift (I went with a Zone spring lift) and, then, add a 1" block lift (I went with the Zone 1" block lift - it replaces the stock block.)
The rear block should always have a taper.

Edited April 11, 2021 by MikeBMW

[JON BAILEY]

Thanks for the info.  Just concerned about all I have been reading on  driveline angles and harmonic vibration

[outerlimits]

Brining this back to life. Trying to find a flat 2" block for my 2017 GMC 1500 to give me 1" of lift. Everything I have seen or ordered is tapered.  

[lucas287]

@JON BAILEY first off, how do you like the 6112s?

 

second, tapered vs flat depends on how you drive. If you use tapered you might get axle wrap if you’re an aggressive driver because you’ve taken away negative pinion angle. It will, however, be smoother the closer it is to statically cancelling each other out. 
 

I use 2 degree shims to bring my pinion angle into compliance with the tcase and then I locked it in with traction bars. No vibes ever. 
 

does that explanation make sense?