[pfilean]

Air domes were often used but if you read a lot of the posts here you will find some confusion on just what got them and when they were discontinued. And they were often removed when a fuel pump needed to be replaced. If the replacement pump did not have one (such as non GM parts) your old guy (I can relate to the age) is right - they just disappeared. Check some of the posts on this subject in the 64-65 GTO Tempest forum.

[Engine-Ear]

DMRGTO's pic shows what every factory-A/C '62 that I have owned (six of them, five built at Arlington, one built at Pontiac).

And FWIW, I haven't seen the air dome on any '62s but I wouldn't say they didn't get them.

[LASJayhawk]

Parts book shows the same dome 1523319 ( group 3.163) used on:
P/8 1958-64 with A/C
T/8 1961-65 with A/C
P/8 1965 389 with A/C

No listing for a 65 421???

[Ziggy]

Thanks, l was not aware of them. But, what was the purpose of the "air dome". To vent the air in the fuel line? To maintain constant fuel presence and remove any voids or air slugs to the fuel pump?

[Engine-Ear]

Originally Posted by Ziggy

Thanks, l was not aware of them. But, what was the purpose of the "air dome". To vent the air in the fuel line? To maintain constant fuel presence and remove any voids or air slugs to the fuel pump?

It is not a vent.

But, much like the air columns located on your basement utility tub's water controls, the small volume of trapped air acts to smooth out pressure pulses of fuel associated with the pumping action, which is probably worse at some RPM than others.

[DMRGTO]

LASJahawk has itright. That is a damper/expansion chamber to diffuse "pulsing" in the system.