What kind of gas cap should I use?
 

Here's a picture of my tank and the catalog states that it's an EEC (Evaporative Emission Control) tank. So my question is do I need a vented cap or non vented cap?

Thanks

Re: What kind of gas cap should I use?
 

Doesn't look like an EEC tank to me, but could be the photo.

EEC tanks have a vent port on the filler neck, and I don't see one there.

If you are using the EEC system, you can use a non vented cap. if you don't have EEC or have plugged it off, you will want a vented cap.

Re: What kind of gas cap should I use?
 

. i have a new old stock gm gas cap for sale if you need it.

Re: What kind of gas cap should I use?
 

Here's a picture of the catalog. Hard to tell if the picture has a vent port on the filler neck but I know my tank doesn't. Well now that I enlarged the photo I see the tube... getting old sucks. I thought the ridges on the neck vs a smooth neck was the criteria.

Thanks Lattimer

Re: What kind of gas cap should I use?
 

Doesn't look like an EEC tank to me. Here is a couple of pics of my EEC tank in my 1972 GMC.

Non EEC tank... run a vented cap. EEC tank... run a non-vented cap. Or like me... have an EEC tank without the EEC hooked up... run a vented cap. :)

Gary

Re: What kind of gas cap should I use?
 

I see said the blind man! :lol: I got it now. No EEC in my truck.

Thanks

Re: What kind of gas cap should I use?
 

You betcha! :)

Gary

Re: What kind of gas cap should I use?
 

The ribbed filler is the "safety filler" a deformable design independent of the EEC. 70 EEC usage was California emission only, 6000lb GVW and below (CK10).