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jltait · 02-17-2011, 05:30 PM

Matt,
I am sure you are correct about needing a shim. By the looks of the pictures the front mount of the Rear leaf springs was moved down some while the rear mount stayed in the stock location albeit the 4x4 mount in lieu of the 2wd mount. However both the front and rear of the rear leaf springs have been changed to 4x4 mounts so the difference (or the amount of shim) should be equal to the angle that the rear leaf front mount moved down. The springs should be 56" so if it moved down 2" you should be able to calculate the angel the RR leaf spring changed and get a shim from DIY4x to shim up the pinion that amount. If you have an email address send it to me, I have a driveshaft setup guide in pdf I can send to you.
JLT

02-17-2011, 05:30 PM	#103
jltait Registered User Join Date: Mar 2010 Location: Eaton Rapids, MI Posts: 97	Re: 85 GMC Sierra Classic 1 Ton Crew Cab Matt, I am sure you are correct about needing a shim. By the looks of the pictures the front mount of the Rear leaf springs was moved down some while the rear mount stayed in the stock location albeit the 4x4 mount in lieu of the 2wd mount. However both the front and rear of the rear leaf springs have been changed to 4x4 mounts so the difference (or the amount of shim) should be equal to the angle that the rear leaf front mount moved down. The springs should be 56" so if it moved down 2" you should be able to calculate the angel the RR leaf spring changed and get a shim from DIY4x to shim up the pinion that amount. If you have an email address send it to me, I have a driveshaft setup guide in pdf I can send to you. JLT