1974ta

I am looking for a quantity of 6 rear bumper bolts with either an "A", "M" or RSC head mark. The bolts are the 1-1/2" long bumper bolts.

I would also like to get 6 OEM 1/2 ID SAE flat washers that go with the bumper bolts.

Thanks,


Bill 301-440-0838

jhudec

Are the bolts you are looking for the same as used on the 68-72 cars? 3/8 x 1 1/2"?
Let me know, as I do have some of these I picked up from a corvette guy in phoenix. I do not have any washers though.

1974ta

They are the same as long as they are grade 5 with the three lines plus the head mark. I am not positive but believe starting in 68 they went to grade 5 bumper bolts versus 67 and earlier using Grade 2.

If you can help that would be great.


Thank you,


Bill 301-440-0838 cell/text

mark6669

I have a what you need $35 shipped
Mark

1974ta

Hi Mark,

Thank you for responding regarding the bolts.

My understanding is they should be Phosphated versus plated.

I may still take them. I ended up finding my originals but might keep these for spares. I do need the washers.

Thanks, Bill

Alan 71

Hi Bill,
My understanding (and the appearance of the bolts on my car) is that the bolts from the brackets to the bumpers were zinc plated, while the bolts from the brackets to the frame were dark….black oxide or manganese phosphate?
???
Regards,
Alan

kenba

What Alan said on C-2 & C-3

1974ta

That is what I thought too. Then I read a very long thread over at NCRS and the consensus was that on 70 bumper bolts the outside bolts were phosphate too. Flat washers were generally plain steel and lock washers were dark gray.

My originals show NO sign of zinc and other original hardware that should be zinc had some obvious remnants which jibed with the thread .



Bill

1974ta

Hi Mark,

Please email me at bogp9@aol.com with payment info.

Thanks,


Bill

Alan 71

Hi Bill,
I just re-read the 26 post thread from 2013. You've been thinking about this for a while!
Quite confusing.
I guess until the next 70-72 TIM&JG appears I'll stay with brite zinc on the bolts if they touch the chrome bumper.
I'm looking at wiper arms in detail now….. many mysteries!
Regards,
Alan

1974ta

Hi Alan,

Very confusing. I prefer the plated bolts so I am going to but these. I will keep my originals as well. Yes I take forever and a lot of times I will read another post or look in the TIM&JM and it will generate questions. Especially if what I took off does not jibe with what I am reading. There is no cure as best I can tell.

I have the original wiper arms for my 70 if you are interested. I also had another original set on the car since the originals are pretty beat up with one of the washer tubes broken. I have original blade holders and one backbone as well. The blades were toast but I did save what was left.

Bill

Alan 71

Hi Bill,
I can understand the darkened bolts being used on the front bumper but not the rear. They're seen from the exterior of the car for goodness sake!
I'd be interested in taking a look at your wiper arms.
I'm planning to go to the regional in Boston next week and Ron G. and I will compare what we have and try to determine what finish was where originally.
I'll probably like to see yours after that conversation since I'll know a little more as to what to look for.
Regards,
Alan

Enoch

I will have to double check but if you look in the AIM there is a different pt # for the four exposed rear bumper bolts and all the untouched cars I worked on from 83-up had zinc bolts. Now that's not to say the assembly line workers never got lazy and grabbed 4 extra black bolts instead of reaching over to the next bin for the zinc bolts. Never say never but in my experience the 4 bolts are zinc (oh and they are 1-1/4") Rich.

1974ta

Hi Alan,

I am going with the zinc.

Hope you enjoyed the regional.

Bill

1974ta

Hi Rich,

I thought the AIM called out 9419077 which I thought are 1-1/2" long. I thought the 9417075 are 1-1/4" wide. The AIM shows the 9419077 going in from the outside which I though made sense since the attach to pretty substantial brackets on the inside.

Bill