Rear axle spacer/bump stop

[jw818]

So I have a 1978 f150 4x4 with a vibration problem I've been trying to figure out. It is not lifted so my question is about the factory blocks under the rear leaf springs. The blocks measure 3.25 inches on the front side and 3 in the rear. The block in my '94 Ford is opposite with the rear being taller. I am not sure if the previous owner put them back on wrong or this is how these trucks were designed. Any help would be greatly appreciated before I decide to swap them to opposite sides.

 

[m78]

The shop manuals give a specific degree of angle on the u-joint. If you could find a way to measure the angle of yours, you can look in the links that Duncan posted and check it.
Just from what you said , sounds like its backwards.

 

[m78]

I just measured mine because I thought they were even front and back, And they are. 3 1/8" .

 

[jw818]

Thnx for the help!

 

[jw818]

Turns out they were on the wrong sides. No more vibration.