67 rear bumper bolts

[Glenn B.]

Looking to replace my stainless steel bolts in my rear bumper with the correct head making. I have the 5th edition Judging Guide, looks as if RBC, SBC, TR, M, and RBW are acceptable, just checking to see if there as been any changes. Its a January car.
Thanks

Glenn
73 Top Flight Nationals

[Gary B.]

Re: 67 rear bumper bolts

Glen,

What I've most often seen on original '66s and '67s are RSC headmark bumper bolts. With a small number of TR bolts in certain locations. I'm surprised the JG does not mention RSC.

Gary

[Glenn B.]

Re: 67 rear bumper bolts

Sorry Gary,it does have RSC, typo. Had the car for a few years, changing a few things as i get to them, want to have it flight judged as some point.
Thanks,

[Mark M.]

Re: 67 rear bumper bolts

To add to this , I've seen a number of original 67s rear bumper bolts with SBC on the head and they had no other marks meaning they are a soft bolt. The earliest I remember was an april car. I don't know if anyone has ever repoped this 7/16 bolt.

[Gary B.]

Re: 67 rear bumper bolts

I don't know about an SBC repro, but the RSC headmark bumper bolts are repro'd by Richard Fortier. They are spot-on based on my comparison woith originals. To the best on my knowledge no one else repros that headmark in bumper bolt size. One step in Richard's repro process is done by hand and the bolts are therefore, shall we say, not inexpensive.

Gary

[Glenn B.]

Re: 67 rear bumper bolts

Everything that I have gotten from Richard Fortier I have been well pleased with.

[Gary B.]

Re: 67 rear bumper bolts

Me too.

Gary

[Peter M.]

Re: 67 rear bumper bolts

Glenn and Gary,
When I did my 67 the 122267 bolts were SBC and 122293 bolts were RBW.
The bumpers had been rechromed at some time but the bolts looked original to me, for what it's worth.
Kind regards

[Gary B.]

Re: 67 rear bumper bolts

Peter,

Clearly there were other headmarks used in '67. But RSC's are not uncommon for '66 and '67. The repro bumper bolt kits sold by all the Corvette catalog companies have an inaccurate version of the M headmark bolt, which is why I was excited when Richard started to repro the RSC bumper bolt about 7 or 8 years ago.

Gary

[Peter M.]

Re: 67 rear bumper bolts

Gary,
I agree, I only mentioned the part numbers to identify the different bolt lengths. They could have been any of the head marks you mentioned.
I was just saying what I found on my car.
Kind regards

[Gary B.]

Re: 67 rear bumper bolts

Peter,

Yes, I recall some are 1" and some are 1.5" long..

Gary

[Gene M.]

Re: 67 rear bumper bolts

More important than the marking of the grade 2 hardware is the finish on the bolt and nut, and the hex nut size between a very early build and later versions.

This was a time of GM finish change as well as an ANSI standard revision on the 7/16” nut hex from 5/8” to 11/16” hex size. Oddly the 7/16” hardware is the only one to have bolt and nut hex differ.

[Gary B.]

Re: 67 rear bumper bolts

Gene,

The 5/8" across the flats (ATF) bumper nuts in zinc persisted into the early part of the '67 model year, to be replaced by the 11/16" ATF black phosphate nuts, which were in fact the exact same 11/16" ATF nuts used at four locations on the large, front ,two center bumper braces that were used since '63.

Gary

[Michael H.]

Re: 67 rear bumper bolts

Glenn,

Just FYI rear bumper bolts and braces are only worth 3 points on originality and 3 points on condition for both sides, so that means each side is only worth 1.5 points . So you shouldn't lose any points if you have the wrong bolts especially if you count all the braces, bolts, washers, etc.

The front is worth 4 points for originality and 4 points on condition.

Mike

[Gary B.]

Re: 67 rear bumper bolts

Mike,

I think it will depend on the judge, and the year. As an example, say on a '63 thru '66, if all the bumper nuts on the car are 11/16" across the flats (instead of the correct 5/8" ATF, except for qty=4), what would you do if you were a chassis judge? On the front and rear combined that comes to 26 incorrect nuts. Would you make a note on the judging sheet, but take no deduct? Or take a 1-pt deduct for the front/back combined?

Gary