Gas Cap for '70 Nova

[67BelAir427]

I know first hand that the cap will not fit the reproduction gas tank that I just installed. I bought the Canadian made tank produced by Spectra, and the stock cap will not fit. We tried a bunch of aftermarket caps and none of them would fit. So I contacted the seller, and was given a part number for the correct cap, available from them and through NAPA.Anyway, the cap says that it is vented(Non EEC) and it fits great.Filled the tank, and after 24 hours in 40 degree weather took the cap off. Gas and vapour shot out the filler neck like a hose. On a hot day, the built up pressure would have blown back through the carb for sure. The only solution was to drill out the vent.Not stock, not pretty and not as designed. I am tired of repop parts that do not fit or work as they should.

[mockingbird812]

Thanks Marc - that has been Schonye's experience too.

Am curious Grady (or M22Mike if u have yr ears on). You sound pretty sure that the cap above would fit the repro tank. Are u referring to yr beautiful '69 burgundy L78 Nova?

[1969grb]

Sam, I have a reproduction tank in the burgandy Nova. I purchased the tank from Quanta. We had an original cap replated for the tank and had no problem with it fitting. I did not think that the 70 neck was different.
Grady

[1969grb]

Sam, Your mailbox is full! Grady

[mockingbird812]

Grady - she's empty now!

[m22mike]

Don't drill your vented caps... ...I am quit sure they are designed to allow some positive pressure in the tank, it helps the crappy little fuel pump work better.
When I have been driving Black Beauty... ...and pull in for gaz, I always crack the cap for a few seconds to allow the tank to vent off. Never tried it after the car has set all night.
If you and try blowing through the hole on the back of a vented cap you will notice it requires a small amout of effort before you get any flow.
The vented cap also has a negative pressure relief built into it as well. You can check this function by sucking on that little round thing in the back of the cap..
For you guys that are not in touch with your masculine side or are
affraid of germs, use a Mighty Vac...

[Salvatore]

WOW Mike, learn something new about you every day! Is this how it is done?

[CamarosRus]

Jack Seymour has experience with this I believe........

Seems to me that the Spectra Premium neck can be modified to accept the correct cap.

I can't say why Spectra Premium neck isnt correct for 70???

[travlnz28]

Is it normal for a "Vented" cap to allow pressure build-up. My 70 Chevelle does it. Should I drill the cap or just leave it alone?

[ORIGLS6]

Mine builds pressure ocassionally. If it gets to be a problem I just loosen it a bit. Just a personal opinion but I wouldn't drill an OE cap.