Correct 63 expansion tank cap

[Troy P.]

I'm trying to sort out what cap markings are correct for my early 63 fuelie(September -October 1962 build). Apparently there are 3 versions of the 307 cap.
1. AC logo 13# and 307 all on one ear and not circled
2. AC logo on one side circled and 13# 307 on the other not circled
3. AC logo on one side circled and 13# 307 circled on the other

Is this correct and which one do I need?

[Tom H.]

Re: Correct 63 expansion tank cap

I would think you would need the first one.

[Troy P.]

Re: Correct 63 expansion tank cap

The judging manual says it does not have a circle around the 307 13# designation but does not mention if there is or is not a circle around the AC. This is the cause of my confusion.

[Stan E.]

Re: Correct 63 expansion tank cap

Original caps had a brass rivet in the center.

[Jeffrey A.]

Re: Correct 63 expansion tank cap

If you have Nolan Adam Restoration Book on Page 86 show you a good picture of what you are looking for I believe.

Jeff Aiello
NCRS 46414

[Peter L.]

Re: Correct 63 expansion tank cap

Stan - The original AC 307 radiator pressure caps used an aluminum center piece so the exposed end at the center of the cover that looks like a rivet is aluminum. Pete

[Paul G.]

Re: Correct 63 expansion tank cap

I think this is the cap in question:

[Troy P.]

Re: Correct 63 expansion tank cap

Good photo. This is the 61 to early 63 cap - the #1 described in my post. I question if the #2 actually exists. It may be an ambiguity in the judging manual. However, Dewitt's on-line catalog indicates they can provide such a cap.

[John D.]

Re: Correct 63 expansion tank cap

Stan - The original AC 307 radiator pressure caps used an aluminum center piece so the exposed end at the center of the cover that looks like a rivet is aluminum. Pete

Peter, When I read Stans post on the brass I said outloud "really". I talk to myself a lot.
Thanks for clearing that up. I have seen some that have been restored though that have the brass rivet and thought they were incorrect. Just yesterday I looked at one and it has the aluminum rivet. The same car also came with a round glove box door key.

[Troy P.]

Re: Correct 63 expansion tank cap

I agree. It's not really a rivet, it's part of the inner pieces and is folded/peened over to hold everything together. None of the innards are brass.

[Timothy B.]

Re: Correct 63 expansion tank cap

Is there supposed to be a gasket just under the top? I ask this because I used a AC doner cap for the sealing gasket and also took the larger gasket and installed it like is was on the doner cap.

[Peter L.]

Re: Correct 63 expansion tank cap

Tim - Yes, the original AC #307 and RC-26 radiator pressure caps with the aluminum "rivet" used a large "fiber" gasket under the large aluminum washer that is directly under the cover. Pete

[Peter L.]

Re: Correct 63 expansion tank cap

John - We've both seen stranger things but brass "rivets" on original AC #307 and RC-26 radiator pressure caps is not something I have come across yet.

With regards to the round head GM/Briggs & Stratton key with the "correct" KEY NUMBER on the KNOCK OUT for the glovebox lock, I believe it is unique to a very special ermine white 1963 coupe with FI; but this is only a theory.

Pete

[Troy P.]

Re: Correct 63 expansion tank cap

Wonder why they don't put the large fiber "washer" in the repo caps? Seems like it would be easy to do during assembly.

[Paul G.]

Re: Correct 63 expansion tank cap

Good photo. This is the 61 to early 63 cap - the #1 described in my post. I question if the #2 actually exists. It may be an ambiguity in the judging manual. However, Dewitt's on-line catalog indicates they can provide such a cap.

This is the cap off my 65 365hp coupe. I thought this cap is correct for a 65 shp small block without air.