Mythbusters, G-body style. Door Weatherstrips Fit Any 2-door G-body. Busted!!!!

[69hurstolds]

GM lower door weatherstrip/seal, p/n- 20008188. This is the RH side, and should fit any 2 door g body.

This was a quote from a recent for sale ad for a 78-80 Olds A-body weatherstrip (which fits nearly all 78-87 A/G Elky/Cabby, 78-81 Malibu, and 78-80 Regals as well) basically saying this particular part number fits all 2-door A/G-bodies from 78-88.

Reference thread:

SOLD - NOS GM Door Weatherstrip/Seal

Up for sale is (1) NOS GM lower door weatherstrip/seal, p/n- 20008188. This is the RH side, and should fit any 2 door g body. The seal is in perfect NOS condition, with all plastic pins in place, and in original GM box. I’m asking $95/shipped OBO.

gbodyforum.com

I personally do not agree with this assessment. Part numbers for others and some pricing are completely different. GM doesn't make sense all the time, but there's a reason they use different part numbers because SOMETHING is different between the parts. Different color, finish, size, materials, or even a different vendor can cause a part number change. It's not a supersession or alternate number, that was already checked. The only "G" body the 188 and 189 weatherstrips are listed to fit is 82-87 G80, which is El Camino/Caballero. The A/G-body Monte Carlo/ GP, and Regal/Cutlass all use different part numbers for the weatherstrips. For real. Why would they do that if they all fit the same?

By sheer happenstance, I recently ran across an NOS set of 20008188 and 20008189 weatherstrips. Hmmm. Why not do a side by side comparison with GM p/n 20201220 and 20201221 door weatherstrips (81-87 Regal and 81-88 Cutlass only)? That should put this claim to bed one way or another. Because if they DO fit every 2-door, then great, you can buy up every 2-door NOS weatherstrip you can locate. But if they don't, you'll need to know that, too, and not waste your money chasing down and buying sh*t that doesn't fit your car. So I bought them. I don't even own a 78-80/81 anything.

It's for factual data gathering. I recall someone asking what the difference was between these two different part numbers many years back, but I don't recall exactly. And I honestly don't know. This comparison should clear it up.

I got to dig out a G-body weatherstrip so hopefully I can get to that this weekend. Pictures coming soon...

 

[SoFloG]

Tuned in. Elco different

 

[69hurstolds]

Tuned in. Elco different

How is it different? Got the correct part number? It's my understanding G80 (body style, not RPO) is Elky, which calls out the same part number as the 78-81 Malibu, so maybe the information is wrong. This is the stuff that needs to be verified and corrected if need be.

 

[SoFloG]

How is it different? Got the correct part number? It's my understanding G80 (body style, not RPO) is Elky, which calls out the same part number as the 78-81 Malibu, so maybe the information is wrong. This is the stuff that needs to be verified and corrected if need be.

I didn't read correctly. Sorry. But yes, needs to be verified.

 

[Rktpwrd]

So now I’m confused. Does the 188 ‘strip fit the ‘78-80 cars or not? I was sure I read in the original post that you said it did, but this sentence from you above “The only "G" body the 188 and 189 weatherstrips are listed to fit is 82-87 G80, which is El Camino/Caballero.” now has me thinking otherwise.

I was the buyer of that sale, so I definitely have a vested interest in getting to the bottom of this.

On a related note, if the ones you just bought are indeed the proper ones for the ‘78-80 cars, I would be very interested in buying them off you when you’re done your comparisons.

 

[ELCAM]

 

[69hurstolds]

So now I’m confused. Does the 188 ‘strip fit the ‘78-80 cars or not? I was sure I read in the original post that you said it did, but this sentence from you above “The only "G" body the 188 and 189 weatherstrips are listed to fit is 82-87 G80, which is El Camino/Caballero.” now has me thinking otherwise.

I was the buyer of that sale, so I definitely have a vested interest in getting to the bottom of this.

On a related note, if the ones you just bought are indeed the proper ones for the ‘78-80 cars, I would be very interested in buying them off you when you’re done your comparisons.

You don't have a G-body. So don't worry about it. Calm down. You're good.

Yes, it fits either one of your Oldses. And also Buick A-body 78-80 cars as well, both buttless and notchback. In this instance I'm not sure we can simply group the A and G's into the generalized "G-body" all-encompassing definition. There's seems to be a definite break at the end of the Olds/Buick A-body for 1981, and 82 for others. And then it carried over from 81 to the G-body Olds/Buick G-bodies from 82-end.

And 78-81 Grand Am/Lemans as well. These fit most A-body 78-80 cars and a couple 81s. From what I gather, though, they only reach into the 82-88 G-body Again, I think the Monte Carlo and GP did not share these weatherstrips. Maybe. Because all the weatherstrips could interchange, right?

What I meant about the "only G-body" they fit was the technical G-body from 82-87 in the El Camino's case. Those part numbers are not listed as fitting anything else past 1981. That's what this comparison will figure out, at least on the "fits all" standpoint. It has to be the same as an 81-88 Buick/Olds 2 door or it fails and considered busted. If it does fit the other cars, then it's a win win.

I did a little digging around on the El Camino forums and from several posts I've read that 78-81 Malibu and 78-85 Elky doors are THE SAME and will interchange. They will also interchange to 86/87 Elky, but the mirror holes were stamped in a slightly different location in 86 and 87 for the El Camino, but that was stated as the only difference. The doors would physically fit on the car. Just would have to use the El Camino side windows. Is this true? If that's the case, then the weatherstripping would also be the same.

Parts book seems to confirm that A27 (Malibu) and A80 (El Camino) had the same door shells. What say you, El Camino/Cabarello owners? The doors were 20138870 and 20138871, which superseded to 20175242 and 20175243 door part numbers (shown below) and then were superseded by 20298408 and 20298409.

They APPEAR like different part numbers, because they are. It just can be confusing because they don't show up as a supersession number, but it is.

The 86-87 El Camino had a new part number. Likely because of the stamping of the mirror holes being in a different place? These are NOT supersession numbers.

I'm not sure what I'll do with them after comparing them. If they fit my cars, you ain't getting them. If they don't, I'm probably going to shred them when I'm done.

 

[Rktpwrd]

Thanks for clearing that up Mike, it oddly kinda makes sense now. Just as long as I’m not now saddled with a purchase that doesn’t fit anything I have. I wasn’t getting all excited, I just found the two posts somewhat contradictory.

Of course I didn’t expect that you’d sell them if they fit your cars, I just wanted to try and get first dibs on them if they didn’t. Please keep me in mind on those, it would be much more financially beneficial to you to sell them to an old hack like me than to shred them! 😅

 

[pagrunt]

Here's what I dug into for these weathestrips.

For the 37 coupe, Monte Carlo for '78-'88 & Grand Prix for '81-'87 will be 20277448 RH & 20277449 LH. I don't have access for a Pontiac '76-'81 parts list so I'm not directly including '78-'80 but I'd say they will use the same p/n's as '81-'87.

As already noted for 27 coupe & 80 pick up delevery Malibu for '78-'81, El Camino & Caballero '78-'87 uses the 20008188 RH & 20008189 RH. Again with the Pontiacs, the '78-'81 Lemans & '78-'80 Grand Am no p/n access but due to the fact those do share the same doors I'll also include them as using these p/n's.

Here's something of note, the 09 aero back coupe, '78-'80 Century & Cutlass use the 20008188 RH & 20008189 LH.

Then there is the 47 coupe, this is what will be something to note. The '78-'80 Regal & Cutlass also use the 20008188 RH & 20008189 LH, but the '81 Regal & Cutlass goes with p/n's 20201220 RH & 20201221 LH. These are also listed for '82-'87 Regal & '82-'88 Cutlass. I don't have access to '83-'87 Buick books but since the same door is on bath the Regal & Cutlass I'm also including those years.

This should be a good reference to guess what OE p/n interchanges with which coupe.

 

[69hurstolds]

No pics at the moment, but at first blush right out of the box, the two A-pillar ends are different. The G-body (81-88) version, same side, part number 202012211, is a bit longer on that end than the 78-80 version, p/n 20008189, and appears to have a different curvature where it fits the door. It LOOKS like the length between the vulcanized ends is about the same, at a nominal 79", but again, not scientific.

Still unverified, but it appears the mounting pin spacing is also noticeably different at first glance. No time to get into it further, but that's what I'm seeing at the moment. Thusly, right off the bat, the myth is BUSTED.

But I'll try to investigate more and take the pics to show these and any other differences I find.