Argh! Core support bolt square washers are turning.
 

I was afraid this would happen. I have the body mount hardware kit from Classic Industries and I thought the core support square washer was a bit small. Mine are turning instead of locking up against the side of their core support recess. Anyone else experience this?

I am going to go out here in a bit and see if Tractor Supply has a grade 5 standard bolt I can substitute.

*3 tick marks on a bolt head is "grade 5" correct?*

Re: Argh! Core support bolt square washers are turning.
 

If it was me. I think I would use grade 8.

Re: Argh! Core support bolt square washers are turning.
 

Why not make the square washers a little longer on one side by welding an extra piece of flat stock to them? You'll never get a wrench on that bolt if you need to make adjustments after the radiator is in.

Re: Argh! Core support bolt square washers are turning.
 

No access to a welder right now. I have thought about making my own washers in the local welding shop (school) but those would be mild steel only.

Good point though! I may reconsider.

Re: Argh! Core support bolt square washers are turning.
 

Yes, add 2 to the # of "marks" on any bolt to get the grade. The symbol donates the company that made it. I may be wrong but it's the bolts grade that would be MORE important, not any washer.

Re: Argh! Core support bolt square washers are turning.
 

Try to get a bite on the cap of the carriage bolt with locking needlenose ViseGrips.
I think that's what I used.