Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

[Richard G.]

Your collective knowledge is need again!
My attempts to identify where these bolt came from has not worked out.
Likely original to my 63 Corvette, but no guarantees.
I did have them re-plated in Zinc sometime in the past.
I have four of them and they are;
7/16 X 1-1/4 NC with WB head markings. Heads require a 5/8 wrench. Grade 8.
I thought it would be easy to figure this one out because of the grade. I was wrong.



Thanks in advance.
Rick

[Edward D.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

Those appear to be the front lower bumper bolts. Attach the lower bumper horns to the lower brackets. Also, I believe they should be black oxide, not plated.

[Edward J.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

I agree with Ed D., Lower bumper braces Should be Black phosphate or Oxide.

[Tom D.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

Are they on the Paragon Poster (page one or page two) that Richard Fortier put together several years ago?

[Richard G.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

Thanks
I now realize/remember that when I sent them out I made the plating mistake.
I actually have a picture of the reproductions and the originals side by side.
Reproduction is black and the original incorrectly plated in Zinc.


What threw me was the grade.
Why a grade 8 application on the flimsy front bumpers is beyond me.

I am attaching a picture of the spacer for these bolts.
It indicates the width of the spacer as received from Paragon.


thanks for the quick response.
Rick

[Gary J.]

[David B.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

Curious if you have a part number for those bolts. If it is 9418890 it is 2 1/4" long as shown by ruler. It is a special GM grade 4435-M code A which is phosphate coated special salt spay tested.

[Leif A.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

I seem to remember that these bolts were zinc plated until mid-way thru production in 1967 when they went to the black phosphate and a larger nut. What am I missing?

[Gary B.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

Leif,

I think those four bolts were black phosphate for most of the C2 era. Definitely Bl Phos for '65 thru '67. Also, those bolts always took a "heavy" nut that was wider than standard nuts. And the nut is the standard 11/16" across the flats for that thread size, unlike all of the other bumper nuts for '63 thru '66 that are "light" nuts that are 5/8" across the flats.

Gary

[Leif A.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

Thank you Gary.

[Richard G.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

Yes the bolt is part number 9418890 just like you said. It is on pg 206 of the assembly manual.

Yes, I had to shorten my spacers. One side more than the other because some idiot had hammered on the lower end of the bumper and peened it over some.
If you can insert the spacers before setting the bumper in the lower struts you can likely get by with less shorting of the spacers.
Mine weren't even there any longer. I know it was worked on by the local Chevrolet dealer in the early 70's. Not impressed with the work.

I mixed up the bumper bolts when I shipped them out for plating. Black ones are Zinc and the Zinc one were plated black. Still have most the bolts.
Ebay had a full set for stupid money a while back. I'll get it correctly plated some day. Reproductions on there now.
Rick

[David B.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

Leif,

I think those four bolts were black phosphate for most of the C2 era. Definitely Bl Phos for '65 thru '67. Also, those bolts always took a "heavy" nut that was wider than standard nuts. And the nut is the standard 11/16" across the flats for that thread size, unlike all of the other bumper nuts for '63 thru '66 that are "light" nuts that are 5/8" across the flats.



Gary

??? Do you have a part # for those "heavy nuts" ?

[Richard G.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

9418897 is the heavy nut part number.

When I worked in industry many business used the heavy nuts as the standard nut in the maintenance parts bins.
One advantage is the mechanics would not have to carry two of the same size wrenches.
Of course Channellocks were the preferred other wrench any way so it made little difference.

[Bill S.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

Are they on the Paragon Poster (page one or page two) that Richard Fortier put together several years ago?

hat poster is that and were can t be found? TIA
W

[D S.]

Re: Find the bolt application (Again) 7/16 X 1-1/4 NC WB head

I hope this helps.