69-72 rally wheel (AZ) identification help

[Greg L.]

I'm just trying to get straight in my head how to tell in particular a 69 rim from a 79 rim.

The way I understand it so far is that a 69 rim will have a "TRA" stamp on the inner surface that can not be seen with the tire installed. Is this what the "TRA" stamp looks like?

This is a 72 rim.

It should also have a "welded BB" or what ever it is called on the outer rim area that was for indicating the heavy/high spot of the rim. Is this what this feature looks like?

This is a 69 rim.

If I'm not mistaken these two features are the only or at least the best way to tell a 69-72 rim from a 79-82 rim....correct?

Greg Linton
#45455

[Mark #28455]

Re: 69-72 rally wheel (AZ) identification help

Basically, if you take about 5 seconds with a MIG welder, you can make an "NCRS correct" 1969 rim from a 1979 rim and it would be essentially undetectable as long as the tire is on.
Mark

[Chuck S.]

Re: 69-72 rally wheel (AZ) identification help

I have never heard of the "TRA" stamp, but those stamps look just like the ones on the inside of my 70 wheels. I think later replacement wheels have a slightly different year format using two(?) digits, but I don't know if this system began as early as 1979. I have a replacement wheel around here and I wanted to check the date format, but it's buried under the other tires/wheels.

The picture you show of the "weld BB" is somewhat atypical in that it appears flattened almost like a rivet head, but I wouldn't try to argue that it's not original. What I will say is, it doesn't appear to be a typical weld spot...depending on the heat and duration of the weld, these BBs can appear as a rounded sphere of weld metal, sometimes with several tiny spheres around the larger one as weld splatter, OR as a flattened raised pool of weld metal with edges that flatten into the wheel, possibly with some under-cut in the wheel metal around the perimeter. In virtually ALL cases, you will see a very small "pimple" on the very top of the weld spot where the electode wire was pulled away from the molten pool.

If the weld BB shown in your picture is original, a non-NCRS enthusiast must have tried to "cosmetically improve" the wheels's appearance by hammering the weld BB flat. I can't say how the weld will fare in judging...it'll probably fly; if ANYTHING is where the weld bead is supposed to be, most judges will give you full credit. The only reason for someone to ADD a weld spot to a wheel is to try and duplicate the "weld BB" for NCRS judging.

[Terry M.]

Re: 69-72 rally wheel (AZ) identification help

Not all early C3 wheels had the weld BB, so don't use it alone as a litmus test of originality.

[Greg L.]

Re: 69-72 rally wheel (AZ) identification help

Well thanks for the replies guys.

I really don't want to replicate this weld mark because to me that would be no different than restamping a carb or engine block but if I can't find a correct wheel before the car is ready for judging then that is likely what will happen with the spare only.

I did talk with the owner of this wheel and he confirmed what I remember about it's originality. He bought the car from the original owner in late 1970 and the first time he removed it was a couple years ago when he started the restoration. I know it doesn't look like a typical spot weld but he assures me that he didn't even know about this identifying mark until I asked him for the pic so he wouldn't have messed with it. In fact, up until a few years ago he didn't even know about the NCRS. I'm just trying to get an idea of what to look for in Pomona next month so that I don't end up buying a 79 rim instead of a 69 one.

I don't know when they went to a two digit year code but I can say that my Feb 2/79 rim has a 9 for the year and my July 7/84 rim has a 84 for the year.

Terry if not all early C3 wheels had this weld mark then is the "TRA" stamp proof positive or is there something else that I should be looking for?

[Terry M.]

Re: 69-72 rally wheel (AZ) identification help

I believe no one item is proof positive. Years ago (around 2000-2001) there was a two-part story covering ralley wheels in The Restorer. There are about four or five features (as I remember) to look for. Some are only visible with no tire on the rim, so they are not useful to us in judging and I tend to forget what I do not regularity use.

Without consulting those articles, I would be sticking my neck out -- but:
Date at valve stem
Date on wheel spider
The logo stamp you mention
GM stamped on the spider
The 15 JJ stamp in the wheel drop center

Those are all I can recall this late at night, but I highly recommend you get those wheel stories -- they should be in the C3 encyclopedia from the NCRS store -- check with Eric to be sure. There are different features of the wheels that can separate one decade from another, and they are identified in those stories.

[Greg L.]

Re: 69-72 rally wheel (AZ) identification help

Thanks Terry. I have those issues of the Restorer on CD and that is where I picked up a lot of my info so far. There is sooooo much good info there that I was having a hard time trying to figure out what I needed to know. I guess I'll just have to go back, sit down and figure out just what pertains to the 69 era.