Gas cap identification
 

Seems AC RC 15 caps come in all sorts of designs with no end to a definitive id. Some have both the AC and RC-15 circled. Some only the AC circled and others without any circles. Even the Corvette guys can`t agree and I occaisionally doubt some of their conclusions as well. I believe I read that most agree the single circled AC is the 64 era GTO cap. I`m sending mine for resto and I have 3 original differently marked big ear caps to choice from. GURU`S?

Gas Cap?

Did you mean Radiator Cap?

oops. radiator cap for sure . Thanks

Is the one from Ames correct for '64? From what I've seen, it fits the bill for a "correct" '64 radiator cap. At $26, it doesn't put a huge dent in your build cost.

I've seen "original" AC caps on ebay for hundreds of dollars. I'd challenge anyone to discern one of them from the Ames version, P155A. The most obvious difference would be that if the "original' cap was truly NOS, the zinc plating would be faded from age, whereas the Ames cap would be bright zinc like when the caps were new in '64.

Here is one of them on eBay right now. https://www.ebay.com/itm/NOS-Origina...hUo~Aa&vxp=mtr

Dick that ebay item has a button rivet and mine are either hollow tube rivet or a flat style. More to think about.

Radiator Caps
 

Just my opinion, but I disagree with the above thought.

I have studied the GTO AC large ear radiator caps for years. The low mileage Survivor cars is what I have used for my research. Yes, a cap on one of these cars could have been change out at some point, but I doubt it.

I have folders that show a super low mile 64 Catalina (pic 1) and the 8000 mile 64 GTO (pic2).
My early 65 still has its original cap (pic 3) and it’s just like the 64 caps. No Circles.

Pic (4) is another one I have which is the same style, but much nicer.

Last photo is the cap on my 66 Survivor which has different font and circles.

The hollow rivets are first design. The flat rivets came on the later caps.

Chris

X2 Chris. "Bill"!

I agree and will send in my non circle caps. I also think that only a magazine or brochure pic from the same era as the car would be useful proof. A so-called original car is subject to any number of alterations regardless of the original owners claim. But why would a very original appearing 64 with very low mileage ever get a new cap? Well I can tell you that we received promotion materials almost daily at chevy. They included product push that included AC and or Delco, and any consumables that could be replaced. Belts and filters were also favorites and we made sure that our route man (salesman) from the dealership hauled flyers and extra rad caps and belts, sometimes offering volume discounts. The Service Manager also was alerted and again pushed service sales and products. Any original cars need to be held as valuable but certainly no where near proof that the parts like a rad cap was original to the car.
I just had another thought. I have several AC parts in boxes that have a date. That would also help establish cap design if someone had a boxed cap from 63-64.

Dear god, it's a radiator cap. If you want to be correct, buy an NOS one, they are out there. That is the only way it will be correct. A "restored" one will never look correct, it will look "restored". Stop listening to Corvette people, they'll turn your brain to mush.