What is correct '71 radiator cap

This is an older picture of my car and a picture in the '71 chassis service manual. Manual clearly illustrates the dial aligning cap. I have seen other caps on '71's so, I've got to ask, what is CORRECT sir?
Troy

 

From everything I have been told and researched, the AC RC29 is correct. I think the smooth cut edge is more correct than the serrated edge. The first picture is a reproduction cap and the second picture is an original cap. Note the difference in the center rivet and the way the nameplate attaches to the cap.

 

Does this cap also apply to the 1970 radiator? Both early and later builds?

 

Yes it does, Ray.

 

I just bought one of these repro caps (the one from CARS) and noticed that the top piece with the printing on it spins around. I assume it is supposed to be held in place by some small tangs, but they are almost non-existent. Anyone else notice this, or am I just blessed?

 

Cars reproduced the cap so the name plate would spin. They did this for a reason.

The original radiators had the cut outs for the cap angled specifically, so once the caps were installed tightly, the stripe would line up with the vent tube. Some of the replacement radiators have this in a different location, so when the cap is tightened down, the stripe does not line up with the vent tube.

Cars went out of their way to "fix" this problem, by allowing the name plate to spin, it solved the problems with non-original tanks not being reproduced correctly. Often if you fit an original cap on a repro rad, the stripe does not line up, so the cap has to sit on the rad loosely to align the stripe with the tube.


Their first reproduction cap had a serrated edge, just like the factory NOS replacements. Both allowed the top plate to spin, so the stripe would line up with the radiators used on different models.

This was corrected on later batches to the smooth edge, like the ones originally installed on the cars. The NOS replacements had 2 small cutouts under the edge of the cover plate. Once you installed the cap, you turned it until the stripe lined up with the tube, then with a very small screwdriver, you pushed the nameplate down in the two places to lock it in place. (The box for the NOS parts had the instructions written on the back of the box.)

Again, Cars went out of their way to offer a very nice part, while also allowing it to correctly fit multiple applications.
Duane

 

Thanks for the detailed explanation.

I must have received old stock, as my cap has the serrated edge.

Cheers

 

Yes indeed, another -1 point that is absolutely wrong.
I can understand finding new things that may not have been seen previously, but to deduct points for multiple items that are totally correct is frustrating!
Troy

 

Judges were wrong!

 

The 1970 and 1971 assembly manuals show two optional part numbers for radiator caps and both years show exactly the same part numbers. I’m wondering if the two different numbers reflect the smooth and saw blade edge? My 71 Stage 1 when I got it had a very old worn saw blade edged cap that I think was original. Either way I say either is correct. Always carry assembly manuals with you and you have documented proof. If they tell you your car is wrong ask for their documentation! Having a 71 you are already the red headed step child, so you have to be ready for that! I see you got docked for not having carpets on your kick panels??? 71 did not have carpeted kick panels. At least none that I ever saw.

 

This is 70

 

This is 71. Interesting they chose to use different page for showing part numbers. Opposite page is just blank for each year.

 

Troy, what is your build date? Sorry if I missed it mentioned.
Mike

 

02C

 

Just so we are clear here, and I am absolutely not going to go down this Rabbit hole.

The burden of proof is not on the judges but on the owners. If the judges approach you with a question then it is up to the owner to provide the proof, not the other way around.

When I brought my 69 Motion Equipped car to be judged in the Concours class, I basically had to bring a book with me proving what parts Motion was using at the time when my car was re-done.

Due to the specialness of the car, that had to be done before it went on the show field. I know this was an extreme case but all the burden of proof was on me, not the judges.

This is the last time I will be commenting on judging here.
Duane

 

The issue I face is, my car is not a 1 of 1. No one should have a deduction for a 71 GS because of lack of judging knowledge i.e., Carpet NOT on kickpanels -1, 15" steering wheel -1, radiator cap -1.
Troy

 

Are the judges at the GS Nats unpaid volunteers or paid experts?

 

My guess, unpaid volunteers.
Troy