Bolt Head Markings

[Irby G.]

I'm a bit perplexed. After watching some insane pricing for 'correct' bolts on eBay (it looks just crazy for someone to be paying $50 - $100 for four small bolts), I looked at the repros and they look the exact same to me. Take for instance bumper bolts. Most of mine are correct, but some have enough rust on them to put the head marking illegible or the strength of the bolt in question. Is there something wrong with the repros? Will I take points deduction with them on the car? I mean, the $100 bolt has a 'TR' or 'M' on it and so does the repro.

[Joe L.]

Re: Bolt Head Markings

I'm a bit perplexed. After watching some insane pricing for 'correct' bolts on eBay (it looks just crazy for someone to be paying $50 - $100 for four small bolts), I looked at the repros and they look the exact same to me. Take for instance bumper bolts. Most of mine are correct, but some have enough rust on them to put the head marking illegible or the strength of the bolt in question. Is there something wrong with the repros? Will I take points deduction with them on the car? I mean, the $100 bolt has a 'TR' or 'M' on it and so does the repro.

Irby-----


I would use the reproductions-----gleefully!

[Andre R.]

Re: Bolt Head Markings

Hi Irby,
Actually, correct and original are not synonymous. Yes, a repro grade 8 7/16" corse thread bolt with the proper head markings would be correct for use on your corvette bumpers, but compared side to side with an original GM produced bolt the small differences would become evident. These differences are what NCRS judges are accustomed to noticing. So yes, you would lose some points.

[Gary B.]

Some headmarks are simply not repro'd

Irby,

Also, no one makes a repro bumper bolt with an RSC headmark for mid-year cars, so if your car came with RSC and you don't want to switch to repro M headmark bolts, then used originals are the only option.

Gary

[John D.]

Re: Bolt Head Markings

Besides the bolts you have to be concerned with the correct flat washers and nuts. 7/16-24 x 5/8 nuts. Washers are 5/8 SAE. Repro kits are incorrect on this aspect.

[Bob I.]

Re: Bolt Head Markings

I find the major difference, is in the washers and finish. I know that I've paid way to much for bolts from e-bay . My thinking is the original bolts will have the correst finish. Seems to be my way to figure this out. I believe that I can go wrong, starting MY OWN BOLT COLLECTION to include repo's.

[Alan D.]

Re: Bolt Head Markings

At a show over the weekend and area of point(s) hit always seemed to be the bumper nuts (sometimes included washers), none were the 5/8. The nuts are simple to check with a socket, washers are harder since you must see them, but JD is correct on the repro being Wrong.
Believe the Driveline has an ad for Nuts & Bolts where I found some hard to find itmes, may want to try there.