63 Expansion Tank

[Thomas B.]

I recently purchased a '63 340 hp convertible which was restored some years ago. I'm in the process of checking part numbers and date codes against the NCRS Spec Guide. The Spec Guide only mentions the part number of the expansion tank in the Radiator section which matches but nothing on the date code which I believe to be on the tank below the part number. The tank on my car shows "83L" in that location. Is this correct for a car built mid-February 1963? If it is not correct is this an important part to replace to maintain a numbers matching car? If I keep it the overflow hose outlet nozzle will have to be replaced somehow since it is broken off and also I believe it has an incorrect cap. Thanks for any input on this.

[Harry S.]

Re: 63 Expansion Tank

Tom, that tank was made in 1983. So, at judging you would take a point loss. 20% on date and another 20% on configuration. As you look at the tank all of the nipples are aluminum welded on. The 63 tank is unique as the nipples are all a press fit. The changed from press to welded as the press fit nipples leaked. DeWitts sells the press fit style and will date code the tank correctly. To stop the leaking DeWitts welds the inside, so you can't see the weld and avoid a point loss.

Just let DeWitts know the month your car was built and the VIN number.

[Thomas B.]

Re: 63 Expansion Tank

Harry, thanks for the reply. What would be the correct cap? Does DeWitts sell that also?

[Harry S.]

Re: 63 Expansion Tank

Harry, thanks for the reply. What would be the correct cap? Does DeWitts sell that also?

I think they do, check their website. Others may chime in. I'd look for a good original, a bit pricey.

[Thomas B.]

Re: 63 Expansion Tank

I'll check it out. Thank You.

[John D.]

Re: 63 Expansion Tank

Thomas, Shortly the new 7th edition of the '63-'64 Technical info manual and judging guide will be out. I know that the caps were discussed.
Meanwhile a typical '63 cap is a 307/13# cap. Look on Ebay and see they are not cheap.

Story: I removed the original cap from my '63 and put another cap on it. Meanwhile I lost this original cap for many years.
A few months ago I found the original cap and was so happy. I have to stop hiding stuff. JD

[Thomas B.]

Re: 63 Expansion Tank

Thanks, John. Don't feel bad I lose things for a while all of the time.

[Thomas B.]

Re: 63 Expansion Tank

So, why would they make a tank with a 1983 date code? Were they used on 80's vintage cars?

[Bob R.]

Re: 63 Expansion Tank

They must have continued to make replacement tanks for older cars but they used the current date of manufacture. They were not concerned with keeping the original dates on parts.

[Harry S.]

Re: 63 Expansion Tank

I agree with Bob on the Service Replacement part and date.

As a reminder, the 63 tank does not have any aluminum welds, everything is a press fit. They changed to aluminum welds as the press fits leaked.

DeWitts tanks are welded, but they welded them on the inside so as not to leak and pass judging.

[Thomas B.]

Re: 63 Expansion Tank

John,

I see the manual is in the bookstore. Thanks

[Thomas B.]

Re: 63 Expansion Tank

Quanta Products say they have correct date coded surge tanks with pressed fittings for 1963-64 for $219. DeWitt's are $299. Is there a reason not to go with the cheaper tank?

[Harry S.]

Re: 63 Expansion Tank

Quanta Products say they have correct date coded surge tanks with pressed fittings for 1963-64 for $219. DeWitt's are $299. Is there a reason not to go with the cheaper tank?

An original 63 tank has all the tubing press-fit into the tank, there are no external aluminum welds. GM started the aluminum welds as the press-fit tubes started to leak. Knowing that DeWitts does the aluminum welds on the inside of the tank. Therefore, they can not be seen.

Ask Quanta if their tanks are welded on the inside to avoid leaks, If no, go with DeWitts.

[Thomas B.]

Re: 63 Expansion Tank

Made several calls to Quanta and can't get thru to a real person only an invitation to leave a detailed message. Doesn't say on their website that the nipples are welded on the inside, so at this point would have to assume they are not. Probably accounts for the cheaper price.