63 front bumper bolts

[Frank D.]

Reassembling my front bumpers now and I have a mix of "M" and "TR" bolts of varying lengths....

The AIM Section 14 drawing sheet A2 shows items 4 and 5 for the bolts; part numbers 122283 and 122267 respectively... Is this due to a difference in bolt lengths ? There are only 4 #4 bolts in the drawing (2 on each side) the rest are #5 bolts... The #4s are the two rearmost bolts attaching the center bracket to the frame....

The bolts were mixed up when I removed them, I have four shorter bolts that were in different places between the two sides...

[Joe R.]

Re: 63 front bumper bolts

Frankie,

Earlier 63 had all TR bolts but later (don't know when) the supplier delivered WB's to GM. There were mixed bolts along the way as usually one side had WB's and the other had TR's. Then all WB's started showing up on late 63's and 64's.
The way the stock was delivered to the line could explain the mix of bolts as new stock was on the top of the boxes the workers used. Who knows???

JR

[Leif A.]

Re: 63 front bumper bolts

Frankie,
Don't know if this picture will help or not. The black nuts and bolts are for '67L bumpers.

[Frank D.]

Re: 63 front bumper bolts

Apparently the vendors are selling the "M" headmark bolts now, the "TR"s in repro are scarce some places it seems - the repro headmarks are bad looking anyway. My issue is that I was told that the #4 drawing bolt is 1-3/4" and the #5 is 1-1/4" by someone I trust. This works out oddly on the center brace because a longer bolt in the rearmost hole of the center brace has a lot of threads sticking out past the bolt - it looks odd...

[Bob R.]

Re: 63 front bumper bolts

Just about all of the original bolts I found on my 63 had an "M" head mark and some of the rear bolts holding the bumper mounting brackets were different lengths but had the same head marking. I replaced some of them with reproduction which all had "TR" on them and were one size fits all. I saved the originals which I removed but there is too much corrosion to leave them in place.

[David B.]

Re: 63 front bumper bolts

GM Standards specifies BOLT #122267 as 7/16 - 14 X 1 1/4 zinc
BOLT # 122283 is listed but not specified
BOLT # 122293 is listed as 7/16 - 14 X 1 3/4 zinc

[Edward J.]

Re: 63 front bumper bolts

Frank I am sure that Long Island Corvette sell there kits with a mix of TR and M.

[Frank D.]

Re: 63 front bumper bolts

Frank I am sure that Long Island Corvette sell there kits with a mix of TR and M.

Thanks I got some repro M's and had some repro TRs already - managed to save about 6 original TRs...
Got the bumpers and correct "thick" brackets together today and its all setup, straight, correct and good-to-go.
Thanks All...

[John D.]

Re: 63 front bumper bolts

My 63, the LWC has WB front bumper bolts. Another '63 I had in the 19400 range had TR & M front bumper bolts Joe Ray. John D.

[Joe R.]

Re: 63 front bumper bolts

My 63, the LWC has WB front bumper bolts. Another '63 I had in the 19400 range had TR & M front bumper bolts Joe Ray. John D.

Having a 63 with M bumper bolts just means that (having it) doesn't necessarily mean it's original.
Sounds like the old (my 63 is original) story!

JR

[Rick A.]

Re: 63 front bumper bolts

when we tore Lady, my 1963 Z06 apart she had ALL WB's

[John D.]

Re: 63 front bumper bolts

Jorjorian has a '63 with serial number close to mine Joe Ray. Front Bumpers = WBs.

[Joe R.]

Re: 63 front bumper bolts

John,

Check your response above. You said M's! WB's yes but I doubt any original 63's had any M bolts! Unless of course they were ordered from Long Island. TR's were the most common and WB's later in the year!

JR

[Rich Y.]

Re: 63 front bumper bolts

I have an very original and unrestored February '63 convertible.

The bolts are all WB and show every sign of never being disturbed.