Identifying early and late models -76

[Raymond O.]

I see many restoration parts are labeled for early or late model corvettes. How can I identify whether my C3 is early or late?

[Edward J.]

Re: Identifying early and late models -76

Ray, If you have a Corvette Black Book it details the differences of the later 76 cars. They were using some 77 production parts in the last months. I would think the last month or two of production but I am not sure. Do the restoration parts books give you a break off date of early vs late ? if the parts you are replacing are original use them to help decifer early and late parts.

[Michael D.]

Re: Identifying early and late models -76

Early and late usually refer to specific running changes. There were several for the 76 models, but the big one was the change from the A6 AC compressor to the R4. The 76 judging guide might list a time or VIN range for some of these changes.

[Jim S.]

Re: Identifying early and late models -76

There were a lot of running changes during the 1976 model run. I have two AIM manuals that were liberated directly from Chevrolet Engineering, (a 1975 and a 1976.) It has a lot of pages in the 1976 AIM are identified with "ROLLING MODEL CHANGE".

Starting with the CORVETTE emblem on the tail. The original 1976 emblem was small and fit into an indentation in the rear rubber bumper. Sometime around March (I could be wrong on this date) the emblem was made larger and the rubber bumper was smooth (no longer had an identation) with the emblem attached to the smooth bumper surface. The emblem change is identified on UPC E01 to E12 sheet 10, by Revision, Authority 66745 on 1/26/76. That Authority date is not the date of the actual part change. The sheet does not identify it as a Rolling Model Change.

Now the change from the A6 airconditioning compressor to the R4 is identified as a ROLLING MODEL CHANGE dated 3/30/76. Certain sheets were made INACTIVE and other sheets came on stream on that date. There are lots of RMChanges in the 1976 AIM. They occurred during the 1976 model run and did not occur at the same time.

Jim

[Mike E.]

Re: Identifying early and late models -76

I ordered a 1976 in May of '76 and took delivery in June. At the time Cast Aluminum wheels were on hold. I don't think they were available again until the '77 model year. Mine being a late car had the larger emblem on the rear bumper.

Mike

[Jim S.]

Re: Identifying early and late models -76

My '76 came in around early May. I had a lot of porosity problems with my aluminum wheels. I think that they eventually replaced all 4, (spare had a steel rim.) They also replaced all five of the Firestone 500 Steel Belted radials.

Jim

[Steven B.]

Re: Identifying early and late models -76

The YJ-8 al. wheel problems continued. The first private owned '77 I saw, September 1976, had aluminum wheels. (white/white and red leather interior, YJ-8's, 4 speed, 3.70, white letter Firestones, and all other options) I ordered my '77 August 6, '76 and ordered YJ-8's and sport mirrors. I received notice in October both options were on hold and I had my choice of taking the car in a few weeks without the options or waiting until they became available, with an availability date unknown. I still have the original Firestones, all five with steel belts broken and through the tire.

Steve

[Terry M.]

Re: Identifying early and late models -76

I see many restoration parts are labeled for early or late model corvettes. How can I identify whether my C3 is early or late?

Michael hit the nail on the head in that early or late refers to the specific part change. A car built before that change will be early and a car built after it will be late. Thus your Corvette can be both early and late. Confused enough? Well I will throw some more in the pot.

If your Corvette was built in the first couple of months of MY production it can in general be referred to as early and if built in the last couple of months of MY production you can in general refer to it as late; however neither of those descriptions will necessarily be valid when speaking about a specific item on your car.

The vendors use the "early" or "late" generality so that they are removed from responsibility for selecting the specific part configuration. The car owner has to do the research to determine which part is TFP (Typical Factory Production) for their car. If your Corvette is reasonably intact you should be able to match the part you purchase to the configuration of the part on your car, but if you purchased your Corvette in boxes you have a research project on your hands. The good news is that there are a lot of us here who enjoy that kind of detailed research, so there will be plenty of help available to you both here and at NCRS meets around the country.

[Jim S.]

Re: Identifying early and late models -76

Someday, when I have a lot of time, maybe I will go through my 1975 and 1976 AIMs and try to pick out differences between the two model years and also identify the Rolling Model Changes.

As I mentioned previously, I had one 1976 AIM direct from Chevrolet Engineering. I would have assumed if was complete but who knows? I then borrowed a 1975 AIM and compared it page by page with my 1976 AIM. I think that I copied every page that was different between the 1975 and the 1976. Again, who knows if the 1975 was complete or not. I returned the 1975 AIM to Chevrolet. (I probably should have copied it page by page but there is a limit as to how many of what we called "government jobs" you can get away with.)

Jim

[Terry M.]

Re: Identifying early and late models -76

An old "war story" that may shed some light on your AIMs.
While I was Restorer Editor I was researching a story on the C1 powered folding tops (I am thinking 1956 or 57, but someone would have to look up the story in The Restorer to be sure). There was a copy of the appropriate year AIM from one of the common AIM aftermarket suppliers in the NCRS archives, but it did not contain all the detail the author and I wanted. I was able to find a copy of that year AIM that was copied directly from the files at Warren Tech Center. (No I can't tell you how that came about without killing you. ) To my surprise, and that of several other knowledgeable folks, the copy available to everyone had more pages in it than what was supposed to be the master copy from Warren. This in spite of the fact that the office in Warren was supposed to retain ALL the pages produced, while the remote locations were supposed to remove the old pages when installing the revised pages.

[Ralph S.]

I have a window sticker for a 1976 VIN # 7551 had Aluminun wheels YJ8 $ 299.00

and I have a build sheet for 1976 VIN # 45140 has YJ8 Wheels

[Mike E.]

Re: Identifying early and late models -76

Have a build sheet for 1976 VIN 45140 has YJ8 Wheels

Mike

[Raymond O.]

Re: Identifying early and late models -76

Thanks Edward. I ordered and received the "black book" and found what I needed. My car was manufacturered in October of ''75, so I guess I am early, but I have the late rear bumper... go figure.

Thanks so much for the good advice.

Ray

[Raymond O.]

Re: Identifying early and late models -76

Thanks Michael. I have the A6, and learned from the"Black Book" that my car was about # 6000, manufactured in October of '75.

I really appreciate the assistance!

Ray

[Raymond O.]

Re: Identifying early and late models -76

Jim:

Thanks for the good information. I purchased the "black book" and learned that my car was manufacturered in October of '75... interesting I have aluminum wheels. go figure.

Thanks again!

Ray