72 ZR1 300mile and brake line clips

[Steve L.]

The attached photo taken in January of this low mileage 72, showing the 3rd X-member with the brake line clips. These appear to be bright zinc.

Looking through the archives, there is a lot of discussion on the finish of these clips indicating that the 2 outer clips should be black phosphate.

There seems to be a discrepancy here. Can anyone shed some light on this?

[Edward J.]

Re: 72 ZR1 300mile and brake line clips

Steve, I can tell you the original plating was in tack on my 72, Those clips were zinc. on my car.I talked to a well respected c3 judge and they will except zinc plating, and there may or may not be a a couple of of the clips on the drivers frame rail that were blk. phosphate. There is a lot in the archives on these clips, so there may be some confusion.

[Paul O.]

Re: 72 ZR1 300mile and brake line clips

Steve you have to remember you are looking at a time capsule for a 1972 at that point of production. At points before and after finishes, components, placement and installation may change.

If you are restoring your car use your cars individual items to determine what was used and the finish on them. Do not use just one car outside of your build time to restore it. Look at several cars close to you cars build before and after.

On C3's I have judged and had the pleasure of just viewing The silver finish is the most typical. But have seen black, green and gold wash in different areas on the car and year of build and I am talking 1968 thru 1982.

Paul 18046

[Edward J.]

Re: 72 ZR1 300mile and brake line clips

Steve, How did you like those pic.s of the 300 mile ZR1? Its a time capsule.Although Terry M. saw it first hand and used it for his judging class. in Fla. and said there where a few things touched on the car.

[Terry M.]

Re: 72 ZR1 300mile and brake line clips

Steve, How did you like those pic.s of the 300 mile ZR1? Its a time capsule.Although Terry M. saw it first hand and used it for his judging class. in Fla. and said there where a few things touched on the car.

Terry M? as in from Ohio?
Just remember: "There are no Corvette virgins."

[Edward J.]

Re: 72 ZR1 300mile and brake line clips

Ya Terry, I was talking about you, your ears must of been burning, it lead you to this post. And yes there is no such thing as a virgin. but I am sure there are not many as close as the 72 ZR1

[Steve L.]

Re: 72 ZR1 300mile and brake line clips

Since I have the Casell plating kits, I'm gonna plate half the clip black phosphate and the other half zinc. The judge can decide which side he likes best.

[Edward J.]

Re: 72 ZR1 300mile and brake line clips

Steve, the frame rail clips I would blk phos. the ones on the front and rear cross members -zinc , and the ones up at the master cylinder area -zinc.

[Mike G.]

Re: 72 ZR1 300mile and brake line clips

mine were all the same...rust

[Steve L.]

Re: 72 ZR1 300mile and brake line clips

If you piece together the archives:
- phosphate is left rail and 2 outer clips on the #3 x member.
-Zinc is #1 x member, right rail and center #3 x-member.

The 73 AIM shows the same clip GM# on the left and right rails, so the above doesn't make sense.

In the set of 72 ZR1 pictures, the left rail clips are plated rust, which probably means they were black phosphate.

On top of this all, the vendors kits don't give the complete set, they only have 5 different version instead of 7 and they are all zinc.

This clip thing is a dog breakfast.

I think I'll wait for Carlisle and check out any 73's I find. But I suspect that most will be plated rust.

You wouldn't happen to have the GM# for the double line clip on the left rail for a '72 as shown in the AIM

[Alan S.]

Re: 72 ZR1 300mile and brake line clips

Hi Steve,
All the brake line and fuel line clips on my 71 (6589) showed signs of zinc(?) plating on their surface that had been against the frame.
EXCEPT for these 3, with dark plating and a size stamp. Note the difference in the thickness of the numbers and letters between the center clip and the clip on the left.
Regards,
Alan

[Edward J.]

Re: 72 ZR1 300mile and brake line clips

If you piece together the archives:
- phosphate is left rail and 2 outer clips on the #3 x member.
-Zinc is #1 x member, right rail and center #3 x-member.

The 73 AIM shows the same clip GM# on the left and right rails, so the above doesn't make sense.

In the set of 72 ZR1 pictures, the left rail clips are plated rust, which probably means they were black phosphate.

On top of this all, the vendors kits don't give the complete set, they only have 5 different version instead of 7 and they are all zinc.

This clip thing is a dog breakfast.

I think I'll wait for Carlisle and check out any 73's I find. But I suspect that most will be plated rust.

You wouldn't happen to have the GM# for the double line clip on the left rail for a '72 as shown in the AIM

Steve, part no is 3923695 pass. side rail clips there are seven clips in 72

[Steve L.]

Re: 72 ZR1 300mile and brake line clips

Al, from your pictures, it looks like they are, from right to left, GM 3976010, GM 3976011, GM 3976009 as shown in the attached pdf.
I traced my clips on graph paper. I got the finish by sifting through the archives as best as I could, so I stand to be corrected. Are these the same GM p/n on your 71?

Ed, thanks for you p/n, these are the same ones except I have a qty of 12. They look like the same ones that are rusted in the pictures of the 72_ZR1_300mi. I think I can see some reminants of zinc plating on one of mine.

But I just got a $1200 plating testing kit for work related parts that tests for zinc, cad, chromate, chrome plating plus other metallurgical tests. I'll bring it home this wknd and try it out.

[Alan S.]

Re: 72 ZR1 300mile and brake line clips

Hi Steve
I looked at your drawing. NICE!!!!
I need to gently 'align' the top of the clips with the bottom so I can measure the 'loop' more accurately. Then I can make a call on which clips on your drawing these appear to be.
I'll be back!
Regards,
Alan