Valve stems
 

For 1967: Did Pontiac use one length of valve stem for all GTO wheels and add an extension for full wheel covers or did they have a short one for the dog dish hub caps and a longer one for cars with full wheel covers. thanks

As far as I can tell, they were all short and tire valve extensions like the 274083 were used as required.

Thanks that's great info. Do you know if anyone sells these? I looked at the Ames and NPD catalogs and they don't list extensions. By the way, is the correct valve stem cap the smooth one or the one with the nipple?

Sounds like your into a correct, exact restoration. Plastic, valve stem extensions are available from many sources in many different lengths. NAPA in the Ballkamp line has many of them. I do not know if they are molded exactly like the OE GM ones in your pic. Of course the valve stems themselves are available in many lengths to eliminate the delicate, leaky extensions. I have a bag of 100 2" valve stems I had to purchase and if that length will work, send me a PM and you can have 4 or 8 for postage. I doubt I will ever need them all.

Here are some NAPA part numbers for various plastic valve stem extensions: All are NAPA part numbers, 90325, 90326, 90324, 903262, 903252, 903242.

Thanks for the info. yes, since I am doing this once, I want to be as correct as possible. I do have the valve stems from the GTO catalog so I am surprised that they did not sell extensions. I will check out the NAPA part numbers. That's easy.

I was looking at the '67 Assembly Manual and extensions (item 4) were indeed used with wheel discs:

9422212 for P01 Deluxe wheel discs
9417730 for P02 Custom wheel discs, N95 Wire wheel discs

Great info. thanks for looking it up for me.