2in lift blocks tapered?

[budman k20]

I put on a Tuff Country 2in lift on my 72 K20 and I didn't put the rear spacer blocks in right away. So far I've put 1000 miles on it and it rides rougher than I would like but no vibrations. Now after I put in the 2in spacer blocks in the rear I see they are tapered. Why are my 2in lift blocks tapered? Don't you want the rear pinion angle to be parallel to the driveline? The reason I ask is I now have bad vibrations after putting the blocks in! Anyone else have this problem and what did you do to correct it?

[LONGHAIR]

First of all, no, you don't want the pinion to be in-line with the driveshaft. That makes for no movement of the joint itself. That is not good for the bearings. They need to roll, otherwise they sit in one place and beat up the surfaces were they make contact.
As far as the blocks, if nothing else changed at the time of the install, I would swap them for an un-tapered set.

[budman k20]

Yes I did say driveline... but I was reffering to the engine and trans not the drive shaft. By tapering the blocks the pinion angle is going up I assume to compensate for the lower rear axle position? Everytime I do something to my truck it seems I have to do it twice!
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[snj8198]

Originally Posted by budman k20

Yes I did say driveline... but I was reffering to the engine and trans not the drive shaft. By tapering the blocks the pinion angle is going up I assume to compensate for the lower rear axle position? Everytime I do something to my truck it seems I have to do it twice!
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the taper is so you can tilt the diff angle down to compensate for the lift. pinion angle is usually 2-3 degrees down ward so when torque is applied from the drive line the pinion rotates to 0 under power. Tuff Country cuts this angle into the blocks so you don't have to add a shim to get this effect.

i know your pain, sometimes it takes a couple shots at a project to get it right. good luck

[obijuan]

did you lower the transmission crossmember? sometimes i have seen instructions telling you to drop the crossmember an inch. that will help keep the angles down. however, i think thats a cheap way out. i dont condone it really. it can crack the frame at your trans mount holes if you follw the instructions and use those factory spacers and just move em. maybe 1"x2" rectangular tubing would suffice.

go to tom woods driveshafts website and they have a diagram showing you how each setup should be and the reasons why.

the cure all is a CV rear driveshaft with the pinion pointed at the tcase.