I need to replace my rear control arm bolts. I see that NPD shows grade 8 bolts for this while Ground Up an Year One have the original style for much more $$$. Are these bolts just grade 8 bolts that I can buy at the hardware store. It looks like the original bolts have shoulders on them. is that a concern?

Unless you've got a numbers correct, concours restoration project going on...Grade 8 hardware bolts of the proper length will be fine.

Used with lock nuts!

Peter

If you go hardware store shopping, try to find bolts that are only threaded for the last inch or so. It is best to have a smooth bolt shaft where it rides inside the bushing sleeve.

The shoulders fit into the frame better and do not bind on the bushings.

Originally posted by engineer:
The shoulders fit into the frame better and do not bind on the bushings. Good point.

I just replaced all 4 of my rear control arms using the hardware kits from NPD. They come with the original style lock nuts and fit fine. The part # for the kit is C-5382-150K and is priced at 19.95. You will need two kits.

Oh, these arms, bushings and bolts replaced the ones that were on the car for the last 34 years and 640,000+ miles. ;)

if you are going to use grade 8's make sure you use two washers under the bolt head
I've seen one where they used just one washer and the washer became dished under the bolt head and pounded out the holes and always loosened up
once we installed another set of new bolts we doubled up the washers and then they stayed tight and didn't concave (or dish) anymore

use SAE Washers, not the cheap hardware ones.