Is this fender original or aftermarket?

It's really not that big of a deal, but a friend gave me a drivers side fender over 20 years ago and I stored it away. It "appeared" to be an original since I blasted what seemed like the original paint off down to the metal and sprayed it with epoxy. I'm just now getting around to fitting it on and it seems like an aftermarket. The pic on the left is the one in question, the nuts are welded on the inside. The pic on the right is from an NOS pass side fender I just bought, these nuts match the nuts on the original fenders exact. So does anyone know if these nuts can be used to identify original GM fenders? Or do some look like the pic on the left? These holes are on the fenders inner panel. If aftermarket I will keep looking for another original. Thanks.

Yes the one on the left is aftermarket.

GM replacement fenders should also have GM stamped on the rear of the fender that faces the door.

Stamp for reference


Also I have this old thread that details some of the differences.

Thanks, I was figuring it was aftermarket. I wish I knew that before I blasted and primed it but oh well. I've heard of the GM stamp but even my originals don't have it unless I'm just not seeing it. We've had the truck since new so I do know they are original. Where do I find the thread you mentioned? Thanks again.

My understanding is only the GM replacement fenders have the GM stamp, the original fenders I have had in my hands have not had the stamp.

If you click the blue text in my post above, or there is a link down in my signature that will take you to that thread.

legopnuematic said:

My understanding is only the GM replacement fenders have the GM stamp, the original fenders I have had in my hands have not had the stamp.

If you click the blue text in my post above, or there is a link down in my signature that will take you to that thread.

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Do you know how to identify an OEM hood from aftermarket? I don't see any info on this. I see they are reproducing the smooth front 73-78 hood now, which is what I'm looking for. I saw and like your write-up regarding fenders, just wondering if you know how to distinguish the hoods. Thanks.

As far as the hoods go, and the 73-78 hoods in particular I am not sure of any earmarks to differentiate OE vs aftermarket. However they only have been making them for maybe five years or so, so I'd doubt there are a ton of aftermarket ones out there. At least compared to 79-80 (both OEM and aftermarket) and OE 73-78 hoods.

Andy @bucket I think can shed some light on some of the differences between the 73-78 hoods. I believe its something to do with the latches (and latch holes) and I think the early (like 73-74) hoods lack an extra relief to help the hood fold in a wreck.

legopnuematic said:

As far as the hoods go, and the 73-78 hoods in particular I am not sure of any earmarks to differentiate OE vs aftermarket. However they only have been making them for maybe five years or so, so I'd doubt there are a ton of aftermarket ones out there. At least compared to 79-80 (both OEM and aftermarket) and OE 73-78 hoods.

Andy @bucket I think can shed some light on some of the differences between the 73-78 hoods. I believe its something to do with the latches (and latch holes) and I think the early (like 73-74) hoods lack an extra relief to help the hood fold in a wreck.

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Yes, the '77 hood had a provision for the safety catch that was used with the optional inside hood release. Then the '78 hood had that provision, along with a provision for mounting a hood/cowl crash interlock at the rear of the hood. I had forgotten about the '73-'74 hoods potentially being different, I've got one I'll take a look at.

I was also unaware that the '73-'78 hood was now reproduced. I've gotta get some newer catalogs...

I managed to find some pictures of hood undersides on some BaT listings

1973
1974

And my 76 with its original hood

bucket said:

Yes, the '77 hood had a provision for the safety catch that was used with the optional inside hood release. Then the '78 hood had that provision, along with a provision for mounting a hood/cowl crash interlock at the rear of the hood. I had forgotten about the '73-'74 hoods potentially being different, I've got one I'll take a look at.

I was also unaware that the '73-'78 hood was now reproduced. I've gotta get some newer catalogs...

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73-78 repro has not been out that long. I bought one from Holley, it looks nice and is not flimsy but I can't try the fit until I get the cab back on the frame and mount the fenders, support, etc.

legopnuematic said:

Yes the one on the left is aftermarket.

GM replacement fenders should also have GM stamped on the rear of the fender that faces the door.

Click to expand...

Here's an update: I just got my AMD fender and it actually has the 8 nuts in the front that are pressed/staked in similar to the original. Here's a few pics of the new one and the original. It fits pretty good, but I'll have to "body work" the gap at the door to fender, it's good at the top and bottom but .110 wider in the middle, you can see into the hinge area too much for my liking. The thickness measures the same as the original as far as I can tell, hard to find a good place to check with calipers, plus the original has paint, surface rust, etc. I can't check the fitment 100% yet since it's just on with two bolts but I believe it'll be fine.

bucket said:

Yes, the '77 hood had a provision for the safety catch that was used with the optional inside hood release. Then the '78 hood had that provision, along with a provision for mounting a hood/cowl crash interlock at the rear of the hood. I had forgotten about the '73-'74 hoods potentially being different, I've got one I'll take a look at.

I was also unaware that the '73-'78 hood was now reproduced. I've gotta get some newer catalogs...

Click to expand...

don't forget my buddy I found on craigslist.

Camar068 said:

don't forget my buddy I found on craigslist.

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I'm glad you reminded me. I had forgotten already.