69 upper rad bracket hardware

[Greg L.]

Does anyone know if there is a kit with these bolts and washers? I assume not because I have been looking all over for some with no luck. If a kit is not available then is it possible, based on the part numbers, figure out what the washers and bolts should look like in regards to the type of head as well as how long they should be?


Just curious but why would the one bolt use a lock and flat washer while the other three use just a star type lock washer.

Thanks again.

[Chuck S.]

Re: 69 upper rad bracket hardware

Greg, I may be able help you indirectly with a few fragments. My car is a 70 base engine with C60...this means it has the big block LS5 radiator support and shroud.

An archived thread addresses the type of lock washers used, and where they were used on the LS5 radiator support brackets. Ron Goduti's post confirms the AIM...there is truly nothing new under the sun here: https://www.ncrs.org/forum/archive8.cgi?review=32935

I found my radiator support in exactly the configuration found in the AIM, and as Ron Goduti described. I can't find my records, however, on anything except the single bolt with the lock washer and flat washer: 5/16" NC X 5/8" long, zinc plated, headstamp LE with three radial lines. The LE headstamp MAY work for 69, but I can't say that for sure.

From the archived thread, you are looking for three zinc plated star washers with external and internal teeth for 5/16" bolts. As John Hinckley suggested, the present day Dorman of that part may be a good match. I have mine around here somewhere in a surplus parts box...two of the three were in pieces, so I will have to replace mine also. The flat washer was a large fender type washer as I recall, but I don't have the dimensions unfortunately.

As to why there are three star lock washers and one spring lock washer, I have wondered about this before myself (part of the reason why I remember Goduti's post), and I would love to know the answer myself. I suspect the one location with the spring lock washer may have been used for material handling or some other line related function where they wanted positive heavy duty retention...when they installed the radiator support, they simply reused the fastener at that location. Star type lock washers would seem to be lighter duty, but if it worked for three locations on the support, it should work for the fourth as well.

I was doing some fastener organizing this week...if I discover any more information, I will send it to you.

[Chuck S.]

Correction

The 5/16" NC X 5/8" long bolt referenced above was incorrectly identified...that's actually the bolt that secures the fan shroud to the center top bracket. I'll keep looking for you.

[Joe L.]

Re: 69 upper rad bracket hardware

Greg------

It depends what you're looking for. If you want a kit with "correct" bolt headmarkings, then I know of no such kit being available. If you are looking for a lit with correct length/size bolts + correct washers, then Dr. Rebuild has such a kit available at a nominal cost. Others may, too.

[Chuck S.]

Re: 69 upper rad bracket hardware

Yeah, here it is 68-76E w/o air conditioning...at the bottom of the page center. Looks like Item 1277180, $6.00. If you have air conditioning, get Item 1277182.

http://www.docrebuild.com/dr-r-web/SHROUD4.PDF

Thanks, Joe

[Greg L.]

Re: 69 upper rad bracket hardware

Thanks guys, that helps a lot. I'm not too concerned about the actual head marking as I think you would really have to look to see it however the head configuration would have to be close as that I think you can easily see.

So would it be safe to assume that the bolts from a early 76 would be the same as what was on my 69 or that they would just fit and function the same?

[Chuck S.]

Re: 69 upper rad bracket hardware

As Joe said, I would expect the hardware configuration to be close except for the head stamps, but I haven't seen the kit yet. I am fairly confident from Doc's catalog listing that the hardware on your 69 would have been the same configuration as an early 76 from the factory...if it's accurate for a 76; it will be accurate for your 69. My opinion is Doc tries to get his stuff as accurate as possible, but sometimes, it may only be fully functional.

GM changed fastener suppliers from year to year, and several suppliers' headstamps for any given year can be on the same car in the same application. On my car, for example, the radiator support to inner fender fasteners have three different head stamps (only six bolts total)...the fasteners are all original and identical in configuration: 5/16" indented hex head with integral washer and pointed tip.

No one should expect all the possible headstamps to be stocked for restoration parts when the parts cover a range of many years. I imagine the packager (maybe the Doc, maybe not) would deliberately put NO headstamp in order to cover the entire applicable year range without someone complaining.

I plan to order the kit and use the washers with my original headstamped bolts...that is, if I can FIND them (they're around here...somewhere).

[Joe L.]

Re: 69 upper rad bracket hardware

Greg-----

The bracket retaining lower bolts on both sides were exactly the same for 1969 and 1976. The part numbers for the upper bolts changed from 1969 to 1976. However, I don't think that the specifications for the bolts changed; it was just a part number change for the same, basic bolt. As far as headmarkings go, I fully expect that would likley have changed over the years. There may even have been several different ones used during any given model year.

While many bolts used on Corvettes during this period were "indented" hex head (i.e. untrimmed), I don't think that these bolts were among them. I believe that these bolts were the "non-indented" hex head (i.e. trimmed). Let me know what type you find on the 76.

[Chuck S.]

Re: 69 upper rad bracket hardware

Non-indented, plain hex head is also what I remember for the upper brackets, Joe.

[Greg L.]

Re: 69 upper rad bracket hardware

Oh before I forget...what type of finish did these bolts and washers have?

[Chuck S.]

Re: 69 upper rad bracket hardware

My less than stellar memory is reinforced somewhat by Ron Goduti's post in the earlier referenced thread...Ron said he thought natural or zinc; I remember zinc. I'm pretty sure that's correct for the washers, but the bolts...it's been awhile. Like Ron said, either natural or zinc for the bolts. I expect you'll get zinc from Dr. Rebuild.