I had a lower a-arm u-bolt break. You should change yours too.

[Injected68LS1]

My 68 is a half-ton and came with drum brakes. On these trucks, the lower control arm shaft attaches to the crossmember with two 3/8 u-bolts. Chevy increased the size of these on disc brake trucks because they were breaking.

I finally had one break that I'm sure was 35 years old. Luckily for me it was in a parking lot. I was just idling in reverse with the wheel cranked. SNAP. Not 5 minutes before I was on a major freeway doing 80mph. It was quite surprizing.

So from my experience, I urge all of you to upgrade these bolts for safety. Early Classic has a 9/16 thread ubolt kit that they sell when upgrading to disc brakes. I just finished installing them and I feel much better and safer.