U bolts for trailing arms.
 

My ubolts are 5/8" diameter. When I see the lowering block kits, it looks like they are only 7/16 or 1/2". Is that strong enough?

Re: U bolts for trailing arms.
 

You are only using one bolt per trailing arm - stick with the 5/8".

I had a local 4x4 shop bend up a pair in the length I wanted for my '61.

Re: U bolts for trailing arms.
 

Speedway has various length u-bots for 3" axle tubes. I just found the length I needed after installing 2" lowering blocks made out of thick walled square tubing from an old weight set based on a write up in the FAQ section by the TX Firefighter. I believe the u-bolts I got were 3/4. I would say 5/8 should be fine, but I wouldn't go any smaller personally.

Re: U bolts for trailing arms.
 

There is also this place in the link below .

Link: https://uboltstore.com/?msclkid=9416...16bc510efa36f1