'73 Lower Rubber Air Dam w/Rivets

[Peter G.]

I am starting to drive my '73 LS4 Coupe more and I would like to install the lower rubber air dam that rivets to the hard plastic one above it. This item was put on early '73s with RPOs LS4 and C60.

Does anyone know where this rubber air dam can be purchased or do I have to fabricate one myself?

Same for rivets?

Thanks in advance.

[Ken P.]

Re: '73 Lower Rubber Air Dam w/Rivets



This is the GM one, but Dr. Rebuild has after market ones.

http://docrebuild.com/DR-R-WEB/GLAS68C.PDF

[Peter G.]

Re: '73 Lower Rubber Air Dam w/Rivets

Thanks Ken for the info and picture!

I did contact Doc Rebuild today to order and unfortunately they have been sold out and item has been "discontinued until further notice"?

Any other sources out there that I maybe able to get one from? Unfortunately I am not going to Corvettes at Carisle this year.

Help.

[Kenn S.]

Re: '73 Lower Rubber Air Dam w/Rivets

I'm in the same boat with my '70 LS-5 and C60.

Eckler's has repro's, at least for the '70 (it's not as large as what I see on the '73 photo), and you can get mounting kits. What's missing is the metal bracket (or brackets, can't tell...need to find page in AIM) that you need for strength/support.

If anyone knows where to find these air dams, maybe they know where to find the metal brackets? That I don't find at Ecklers, but I could've missed it. Without the metal brackets, you're hosed. If anyone has one they don't need any more, I'd love to discuss it. Not as hard to find as the durn '70 early C60 LS-5 radiator fan (3969926), but still a tough find. Heck, if you have a fan, I'd really like to talk about it.

[Terry M.]

Re: '73 Lower Rubber Air Dam w/Rivets

I'm in the same boat with my '70 LS-5 and C60.

Eckler's has repro's, at least for the '70 (it's not as large as what I see on the '73 photo), and you can get mounting kits. What's missing is the metal bracket (or brackets, can't tell...need to find page in AIM) that you need for strength/support.

If anyone knows where to find these air dams, maybe they know where to find the metal brackets? That I don't find at Ecklers, but I could've missed it. Without the metal brackets, you're hosed. If anyone has one they don't need any more, I'd love to discuss it. Not as hard to find as the durn '70 early C60 LS-5 radiator fan (3969926), but still a tough find. Heck, if you have a fan, I'd really like to talk about it.

I think I remember a 1973 TSB that showed the air dam illustrations with the brackets, and I recall seeing one on a Corvette at a meet in Steamboat. As I remember the brackets looked pretty crude, and might be fabricated easily. I remember them looking like a simple right angle bracket like one can buy at the hardware store -- that is if function is yoru main goal and judging isn't an issue for you.

[Kenn S.]

Re: '73 Lower Rubber Air Dam w/Rivets

Me personally, judged. So, again me personally, I'll have to look for good examples, take pictures, measure, and then fabricate. Unless, of course, there is a quality repro out there, which there doesn't seem to be. Seemed odd to me that you could buy a repro air dam and set of bolts and not the metal flanges/supports. Of course, maybe those are included with the repro...no photo of the back on their site.

[Peter G.]

Re: '73 Lower Rubber Air Dam w/Rivets

Well in the picture of the LT-1, it looks like the rubber air dam rivets to the hard plastic one above it. Are the metal brackets behind the hard plastic air dam?

[Kenn S.]

Re: '73 Lower Rubber Air Dam w/Rivets

On a '70, yes. But the '70 also doesn't have rivets...uses bolts. I have the bolts, and I see the holes.

[Ken P.]

Re: '73 Lower Rubber Air Dam w/Rivets

Well in the picture of the LT-1, it looks like the rubber air dam rivets to the hard plastic one above it. Are the metal brackets behind the hard plastic air dam?

The air dam supports are just strips of metal with holes in it that line up with the rivets.

[Tom R.]

Re: '73 Lower Rubber Air Dam w/Rivets

The air dam supports are just strips of metal with holes in it that line up with the rivets.

That's what I recall. Bought my kit from Harry Mann for my 73 and the rubber came rolled up and there were two thin black painted metal strips with holes punched into them that lined up with the pre-punched holes in the rubber. Used the rubber as a template to drill holes into the existing plastic dam and then pop riveted the assembly together using small washers under the heads of the rivets in front.

The rubber never exactly followed the contour of the original dam but worked. The car ran cooler after the add.

[Peter G.]

Re: '73 Lower Rubber Air Dam w/Rivets

Since it looks like that I am going to have to fabricate this rubber air dam piece......does anyone know of who sells this piece of rubber? Thickness and texture?


One of the postings said that the pictured rubber air dam was GM and another posting said that he got his from Harry Mann (Chevrolet?). Could this piece still be available or if not still some inventories remaining? How long ago was the purchased from Harry Mann?

[Tom R.]

Re: '73 Lower Rubber Air Dam w/Rivets

Think you're going to be out of luck on the purchase from a dealer. I bought my kit from Mann in 1975.

Peter, see if you can find a strip of rubber about 4" wide the length of your factory spoiler. I would think 1/8" would be about the right thickness. Using scissors cut the ends to look like the ones in the post above. That looks about right as I recall. Punch 4 evenly spaced holes on each side of the rubber like in the photo.

Next, get a couple of 16 ga steel strips ( you may want to look at something from Lowe's or Home Depot in the roof flashing dept) that will fit behind the factory spoiler on each side about 1 1/2" wide. Punch 3/16" holes in each piece to mate up with the ones in the rubber. Paint them matte black. Now drill holes through your factory spoiler then pop rivet the assembly ( from the front, rivet, 3/8" washer, rubber, factory spoiler then backing plates). Should look and function just like the one I bought from GM. I remember looking at the kit when I first bought it that it was pretty cheesy looking for a factory part. So I doubt if you making one like this could be much different than the one 36 years ago.

[Peter G.]

Re: '73 Lower Rubber Air Dam w/Rivets

Thanks Tom and everyone who posted to help me with this!..looks like I have a new Corvette project. Shouldn't be too difficult once I find the rubber piece.

[Ken P.]

Re: '73 Lower Rubber Air Dam w/Rivets

Peter,
I took some measurement for you. I got what I could with the car on the ground.

The rubber piece will have a "V" shape when laid flat see "J" in this PDF. "http://docrebuild.com/DR-R-WEB/GLAS68C.PDF

Using a strip of rubber that is 3-3/8 wide, won't work unless you seam it in the middle. My advice would be to make a template.
The rubber is 1/8" thick and 3-3/8 wide. I couldn't get a good over all length but I did get a measurement from one end to center which is 25"
The rivets have a 5/8" head and are black...looks like they are anodized.
the hole spacing is 7-5/8 except for the center two. They measure 3-3/8 when installed on the car, I don't know what that would be laid flat.
The support strip in the back looks like the metal strapping used on wooden shipping crates. About 1" wide and not very thick.
Hope this helps.
Ken

[Peter G.]

Re: '73 Lower Rubber Air Dam w/Rivets

Thanks Ken for taking the time to take the measurments! It looks like I should be able to make this item once all the correct materials are located.

I also have some very talented co-members in the Rocky Mountain Chapter near by that would help me with this.

I may ask some more questions soon and I will post a picture similiar to your '72 LT1 of the completed project.

Thanks again Ken for the excellent picture of the GM part.