Just that, can't find it anywhere online. My truck has a 3" block under the leaf springs, trying to figure out if that is stock or something that was added at one time or another.

Do they make bigger blocks, 6" or 7"? I don't like the idea of stacking them.

 

That is stock. Larger blocks result in wheel hop. Best bet is taller springs or rear shackle flip with either rewelded spring perches or axle shims. Or combination of both. If you shim, go with steel and not aluminum.

 

Thanks!

Do you know what size shim would be necessary for this truck if I did the shackle flip? I'm guessing I would get about 4" out of the flip?

What causes the wheel hop? The leverage of such a large block?

 

Don't know? No 2 sets of 40+ yo springs are the same.
Exactly. Fulcrum point further away from springs. It will eventually warp the springs and you will have input shaft seal issues.

 

Ah, makes sense.

I'll crawl under tonight and take a look. Do most people just reuse the stock shackles? Just turn upside down and flip sides?

Now to find tapered blocks.