What are the exact specs for rear spring bolts???

[Donald A.]

1970, am wanting to drop rear end just a bit. Want to buy some new bolts. Already have new bushings that came with new 6" bolt kit. Want to go to 8"

Does anyone know the exact diameter of bolt and the thread count they should be. I was at the car last night but did not think to measure the bolt on the car. No online stores give the spec

Doing some online searching results in reports of 9/16 X 8 X 18 thread, grade 8???? 18 thread sounds pretty coarse to me.

Thanks for any help as I would like to find some bolts locally today

regards

Don

[Joe L.]

Re: What are the exact specs for rear spring bolts???

1970, am wanting to drop rear end just a bit. Want to buy some new bolts. Already have new bushings that came with new 6" bolt kit. Want to go to 8"

Does anyone know the exact diameter of bolt and the thread count they should be. I was at the car last night but did not think to measure the bolt on the car. No online stores give the spec

Doing some online searching results in reports of 9/16 X 8 X 18 thread, grade 8???? 18 thread sounds pretty coarse to me.

Thanks for any help as I would like to find some bolts locally today

regards

Don

Don-------


The end bolts are 9/16-18 thread size. The original bolts were GM material grade 290-M. This is 5 lines, a rather unusual material grade.