How to tell a GM cowl hood from a repro cowl hood? [Archive] - Team Camaro Tech

: How to tell a GM cowl hood from a repro cowl hood?

Sep 19th, 03, 10:03 AM
Hey, I have a 69 Camaro with a cowl induction hood.. how do you tell a real GM hood from a aftermarket one like Goodmark or such??


Sep 21st, 03, 07:17 AM
Wow.. thanks for the replies.. that was helpful..

(please note the sarcasum..)

Sep 21st, 03, 07:35 AM
You should check the archives for the answers that are not there from all the other times the question was asked. tongue.gif :D


P.S.- Please note sarcastic reasponse. graemlins/waving.gif

The only thing I could ever see was that the repro I bought did not have the 4 dimples around the mounting bolt holes like the GM one I bought. At least I was told it was a GM hood. The GM sticker came off a little too easy IMHO so now, I am unsure if it was actualy GM. It did fit better than the known repro. The GM hood also had 3 spot welds where the rubber bumper stops ride in the front where the repro had 4 spot welds in the same area. Other than that, nobody has ever been able to conclusively I.D. them.

Some folks argue that the GM piece is heavier but how would you know by looking? A used hood has lots of paint on them so they would definately weigh more so how useful is that?

Sep 22nd, 03, 02:59 AM
I have a GM hood that is vintage 69. I noticed that by the cowl, you can see some very small cracks in the metal at the point of the hood being stamped to form the cowl. Hope I'm making myself clear but it's evidence of the process way back then. You wouldn't see it on the new (er) repros.

Sep 22nd, 03, 12:14 PM
I've been told, but not actually observed, myself, that the front corners of the original hoods were curved downward slightly. The repops are more flat, so that they don't follow the contour of the fender, as well.

Sep 22nd, 03, 02:13 PM
Hey....I just learned this trick today!!!

You can easily tell the difference in the, well....It's probably easier to show a picture....

You see that edge....On a repop it's straight, but on a factory hood there is like a hook molded in. I don't have a picture of a factory hood, but I just looked at three today.

Sep 23rd, 03, 05:44 AM
Hey, Paulm,
I just checked my GM hood, and it has two notches in that lip. one about 8" back from the front edge of the hood,(where your arrow is) and another about even with the front of the hinge. Your pic did not show the hinge area, so I'm not sure if the reproduction ones have the notch near the hinge.

Sep 23rd, 03, 06:18 AM
Hi All,
An easy way to tell a original hood from a repop is, Look at the rear corners of the hood where it meets the cowl and fenders. With the hood open,On a GM hood there is a little kick down or notch in the metal. On a repop there is just a 45 degree angle in the metal. This may sound confusing but if you look at the hoods you can spot the differance from 20' away.
I hope this helps,

Sep 23rd, 03, 07:23 AM
Unreal, could you snap a picture so that we can show the difference in the area that I was trying to describe?

Sep 23rd, 03, 07:53 AM
Paul, is that pic a repro or factory? Ya lost me.
I can snap and post a bunch of shots of a factory one tonight.

Sep 23rd, 03, 10:10 AM
Sorry Joe, mine is a repop!

Sep 23rd, 03, 02:33 PM

Here's 8 shots of an old factory hood. I have a bunch more and larger versions of all if anyone wants them.

[ 09-23-2003, 05:28 PM: Message edited by: HwyStarJoe ]

Sep 23rd, 03, 04:50 PM
Thanks Joe!!!

Here is a difference that is easy to see.....

Repop hood with straight edge:

GM hood with notched edge:

Sep 23rd, 03, 05:24 PM
Wow, now that is easy to see! I just had to go out and check my hoods (standard and cowl) and both have the original notches. Now I have something fun to do at the next car shows :D

I just found out the differences between repro gas tank supports too. Originals have the rear bolt hole slot side to side, repros have the slot front to back.


Sep 24th, 03, 12:31 PM
Does that mean my cowl hood setup is original too? WOW thats cool for a change.
mines bigger than yours nener nener nener :D

Sep 25th, 03, 08:09 AM
Sorry Guys,
That notch does NOT mean that it is a GM hood. I put a Repo ZL-2 hood on my 68 SS/RS back in 1995 that came from Classic Industries and it also has the notch that you are talking about. Just look at the inner stucture in the corners where it meets the cowl and fenders and the differance is plain as day.This is one sure way that I know of too tell them apart. They are probably other ways, but this is the one I know. Heck all you guys that are taking off the flat hoods and installing ZL-2 hoods just compare the two.

Sep 25th, 03, 09:54 AM
Are you talking about that rounded inner layer that doesn't quite conform to the outer shell like in this pic?

Sep 25th, 03, 01:02 PM
Hi All,
No. if you open the hood and stand on the side of the car and look at the rear corners from a side veiw, you will see what I am talking about. On a repo the inerstructure of the hood meets the outer hood panel with a 45 degree striat line. On A Original GM ZL-2 Hood looking at the same angle it has a notch in where the two halfs come together.
if you can take a pics of both hoods from the same angle, the differance is ovious.

Sep 26th, 03, 03:02 AM
Cool... got it. I'll do that and post them here for future reference.

Oct 28th, 03, 08:06 PM
Excellent post. Pictures say it all. I thought my cowl hood was repro, but after checking your pics against my hood, it looks like mine is GM.

69 RS-Z
Oct 30th, 03, 03:12 PM
Can anyone post a picture of the "notch" on the Gm hood? The one referred by yellow 69 z/28. I just wanted to make sure I understood what he was saying.

Oct 30th, 03, 10:00 PM
I also would like to see some pics to see what exactly is meant.
I have an SS-hood laying around here, and it suppose to be the real deal (GM)...just want to check it.

Oct 31st, 03, 05:52 AM
Not sure if this is the right angle, but this is what I got a pic of, should I take pics of different angle?
What does this tell me if anything?

Oct 31st, 03, 06:33 AM
I'm not very smart. I need to see pics of the same area for GM and Repop, in order to understand.

69 RS-Z
Oct 31st, 03, 09:23 AM
Thanks for picture click. So is that hood GM or repop?

Oct 31st, 03, 09:55 AM
Originally posted by click:
Not sure if this is the right angle, but this is what I got a pic of, should I take pics of different angle?
What does this tell me if anything? Not the best angle. but to answer your question, that picture tells you your hood is a GM and not a Repo.

Later today I will try and take a pic of the original ZL-2 on my 69 Z and a pic of my Repo hood on my 68 and post them on my Sig. site.

Oct 31st, 03, 01:10 PM
I put some comparison(sp) pics of the a GM hood and a repo on my website. Just click on the link in my sig. to see them.
I hope this helps,

Nov 1st, 03, 01:51 AM
thanks Nick,
Now I'm smarter. Are the differences you photographed for ZL2 hoods only, or does it hold for SS hoods, too?

69 RS-Z
Nov 1st, 03, 01:51 PM
Thanks Nick. I see said the blind man! graemlins/hurray.gif

Nov 3rd, 03, 05:33 AM
Originally posted by Unreal:
thanks Nick,
Now I'm smarter. Are the differences you photographed for ZL2 hoods only, or does it hold for SS hoods, too? Unreal,
My original SS hood that belongs on my 68 has the exact same knotch as the GM ZL-2 hoods.As A matter of fact evey gm hood I have ever seen looked the same. It didn't matter if it were a ZL-2, SS, or just a flat hood. But Truthfully I never really paid any attention to the repo SS hoods. If I were going to guess, I would say yes the same way of telling them apart would apply.
I hope this helps,

Jan 9th, 04, 04:17 PM
Hello all. I want to say thanks to everyone for the info on the differences between the GM and Repo cowl hoods. I picked up an X33D80 Z about 3 years ago with a cowl hood, which is not original to the car, and had no idea how to tell what it was. The pics are a great source of info. 2 mysteries solved. I have a pic on my website of my Z. It's been painted several times in it's life, (all Cortez Silver paint jobs). So far I have found that the quarters are Taiwan and the tail panel has been replaced as well but not sure if it's a GM or repo. Is there a way to tell the difference between the 2? Other than that, the front seats have been redone and a repo dash has been added. The car was a racer for many years and the original speedo reads 80950. I have since replaced the Weld wheels with rally wheels.

Bob Jenkins
Jan 9th, 04, 07:16 PM
excellent info....thanks guys graemlins/beers.gif

Jan 12th, 04, 02:15 PM
Verified the ZL2 hood on my car is GM by the photos shown smile.gif . Thanks for the info.

Jan 13th, 04, 10:54 AM
The biggest difference is that the later GM hoods don't fit worth a d@mn. The rear edge of the hood does not line up with the cowl panel properly.
Conversly, the Goodmark hoods fit better in that area.

I bought my hood from a GM dealer in about 1994, so I'm sure mine is a GM.

Jan 13th, 04, 02:50 PM
I`ve been watching this post and would never have dreamed it would get so many responses. Seems there is some controversy overy this subject. The best way I have been able to always tell about GM sheetmetal from the repop stuff is simply by it`s weight. The GM hood is simply heavier than it`s repop brother. Also, the rise on a GM hood, be it a cowl or ss hood, is taller than the repop hoods.