I have a 70 Nova could anybody tell me if i need a vented or non vented gas cap. Thanks

Vented!!

i'd say look at the gas tank... if the sender has a return line on it then i'd say it'd be a non vented cap and probably has emission control devices installed. if only one line on sender it'd be vented without emission control devices.

NAPA shows 2 numbers, one for with emissions and one without emissions

http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=430&Keyword=gas%20cap&KeywordCat=Gas+Cap&VehCode=Y

If it has a charcoal filter canister under the hood would be my indicator of the need for a non-vented cap. They were used to capture fumes from the carb (after it was shut down) and acted as the gas tank's vent.

Big Dave

I'm only seeing one fuel line to the front of the car.So I don't believe the car had a charcol canister. Or do I see any other return lines at the tank.So I guess I need a vented cap.The front end was off the car when I got it so I wasn't sure what was there.Thanks for all your Help.:thumbsup:

Yeah u need a vented. 1971 is when they started the return line..etc

i had problems with my vented cap. TWICE it F****en clogged up.
Sent pressure to my carb. This sounds a little nuts, but it worked.
I used the smallest drill bit and i drilled a hole through the cap.
Never had a problem since. But i run a fuel filter before the fuel pump, just in-case:thumbsup:

I asked a similar question today. I checked my 68 tank, it's a new tank put in by prior owner and has one fuel line from sender unit, and hard to see but looks like a small tube open next to the sending unit pressed against the floor board. Is that the vent, or can I say I have a vented tank?

If a vented tank do I need a vented or non-vented cap? I'm a little confused on this.

What you are seeing may be the rubber boot on the sending unit wire. It is black and round like a rubber hose. The wire comes out of the side of the boot and should be routed toward the rear of the car. It enters the trunk above the filler tube near the license plate bracket. It should be a brown wire.