Bumper nuts: �67 vs. earlier C2

[Michael H.]

Michael,

I suppose you say that because "black" phosphate was more gray to dark gray than black?

Gary

Gary,

Yes, I think a lot of items that were plated "black phos" actually came out grey instead of black.
If you bring something to a plater today and ask for black phos, the plater would probably make sure the parts were black.
I don't know exactly what causes most production black plated items to be grey instead of black but I have to guess it would be because the items were quickly dipped, or only partially plated.
I'm sure someone that knows more about plating can tell us what the story is.

[Ronald L.]

[Scott S.]

My March 30th 67 has the 11/16 nuts on the rear bumper bolts. Dale

Just got to my bags of bumper nuts and bolts recently. Many of my bumper bolts were incorrect. Of the ones that were original, I have six GM 122293 and two GM 122267.

Of these, I am sure of the location for four of the 122293 bolts, they were being used with the Item 5 rear braces (UPC 14-B1). The labeled bags (LH & RH) include the shims (some stamped "M", some stamped "W") along with one split lock washer and two flat washers, just as indicated in the AIM.

The nuts are 5/8" ATF, and appear to have been Cad-plated, but I can't tell for sure.

January 11th, 1967 coupe.

Anyone else check their 1967 bumper nuts?

[Scott S.]

[Peter L.]

[Gary B.]

Gary - OK. This shows what one Corvette "nut" won't do for another Corvette "nut." I finally crawled under 67 S/N 1476 and checked the nuts on the rear bumper bolts and all of them use a 5/8" socket. Pete

Peter,

Hmmm. That's very interesting. Maybe early '67 cars used left-over 5/8" across the flats nuts from '66.

Thanks for checking.

Gary

[Ray G.]

[Timothy B.]

[Gary B.]

Hello Gary;

After your research on the TDB and other sources.

What is your conclusion?

Ray

Ray,

Scott Smith is assembling a summary of the data so far. He should post something in the near future.

Gary

[Scott S.]

Ray,

Scott Smith is assembling a summary of the data so far. He should post something in the near future.

Gary

Now I'm on the hot seat


Here's a re-cap of the information so far:

1. Pete Lindahl's early production (VIN 1476) has 5/8" Across-the-Flats nuts for all rear bumper nuts

2. Tim Barbieri's September 23rd, 1966 (VIN 15xx): to be determined

3. My January 11th, 1967 coupe (VIN 07873) has 5/8" ATF bumper nuts on the rear inner braces (UPC 14-B1, Item 5, Brace-Inner Upper, L & RH), those are the only examples I have cause to think are probably original

4. Dale Schafer's March 30th, 1967 has black phosphate 11/16" ATF for all rear bumper nuts

5. Jerry Fuccillo's June 29, 1967 convertible has all black phosphate 11/16" ATF bumper nuts (front and rear)


If the 5/8" nuts found on my rear inner-upper braces (Item 5) are original, then it would appear that the change over occurred shortly after my car was built and shortly before Dale Schafer's car was built, which is about a 50-day window.

More 1967 data points are needed.

[Gary B.]

Bumper nuts: When the changeover?

Thanks Scott.

Presuming Tim reports back on his Sept car as having the 5/8" nuts, then I'd agree with you that that changeover happened sometime between January 11 and March 30. As time goes on and some of us continue to look at more Jan-Mar 67s, maybe we can narrow it down to a smaller window.

Gary

[Michael H.]

Re: Bumper nuts: When the changeover?

Thanks Scott.

Presuming Tim reports back on his Sept car as having the 5/8" nuts, then I'd agree with you that that changeover happened sometime between January 11 and March 30. As time goes on and some of us continue to look at more Jan-Mar 67s, maybe we can narrow it down to a smaller window.

Gary

Did the part number for the nuts in the 67 AIM change at some point?

[Gary B.]

Re: Bumper nuts: When the changeover?

Did the part number for the nuts in the 67 AIM change at some point?

Michael,

No.

The part number changed from the '66 AIM part number when the '67 AIM came out, i.e., there was never a revision note. Just a different part number starting in '67.

Gary

[Michael H.]

Re: Bumper nuts: When the changeover?

Michael,

No.

The part number changed from the '66 AIM part number when the '67 AIM came out, i.e., there was never a revision note. Just a different part number starting in '67.

Gary

Thanks Gary. I was just curious. Looks like they continued using up 66 inventory on early 67's.

[Gary B.]

Re: Bumper nuts: When the changeover?

... Looks like they continued using up 66 inventory on early 67's.

Micheal,

That seems to be the case; maybe 4 months or more of '66 inventory.

Gary