What size gas cap
 

I just picked up a new gas tank for my truck and need a new gas cap for it. The tank has a larger opening for the cap so the stock size cap not longer fits. Anyone have this tank and know what gas cap would work? The tank I have is in the link below.

http://www.tanksinc.com/index.cfm/pa...rod/prd337.htm

Re: What size gas cap
 

If your truck is a 72 and to small you would need one for a 67-71 tank

Re: What size gas cap
 

measure the hole and go to local autoparts store ask for proper size cap to plug hole

Re: What size gas cap
 

The tank has EEC so it isn't a vented cap like the early year trucks. I was hoping someone had this problem before but if not I guess I will just go to a local store and see if I can get lucky.

Re: What size gas cap
 

Im not sure if this is your problem or not but 1/2 ton trucks had smaller diameter caps than 3/4 ton trucks.

Re: What size gas cap
 

I'm in the same boat as you. I have a '72 1/2T w/EEC. I purchased a replacement fuel tank from LMC, part number 32-5923 for a '70-72 1/2T w/EEC. The tank I received has a 2-1/4" filler neck (measured at the gas cap opening). At the same time I also purchased their gas cap, part number 32-4127 for use with this tank. This is their only listing for a 1/2T '72. The new gas cap fits my original tank with a 2" filler neck perfectly, but is obviously too small for the new tank.

Looking at their catalog again I now notice a note separate from the part numbers themselves that says: "Replacement gas tanks #32-5922 and #32-5923 (mine) are 1967-71 design. They can be used on 1972 models but require the use of 1967-71 gas caps only. Both tanks are equipped with 2" filler necks." Grrr! Seems to me this note should have an asterisk connected to the Gas Tank heading and/or part number so people like me don't miss it, and they should have an internal flagging system to note the incompatibility when ordered together. I assume what they call a 2" filler neck is measured away from where the cap screws on, or else this note is incorrect. So much for keeping it original looking.

Who sells an original '72 EEC tank with the correct filler neck?

Re: What size gas cap
 

I went to NAPA and found that NAPA/Balkamp part #703-1060 fits the LMC universal tank with the larger '67-71 style filler neck for EEC, and is otherwise of the same configuration as the original smaller diameter cap. It is 1/8" wider at the ears where it screws into the filler neck, than the smaller size available (1-1/2" vs. 1-3/8"). Part #703-1092 is listed as the replacement for the smaller diameter original.

Re: What size gas cap
 

Like you guys have said, an earlier year cap was the fit for my tank. I just went out and got a '71 Stant cap and it worked great.

Re: What size gas cap
 

I just installed a new EEC tank for my 72 from RockAuto. Stock cap was too small. 68 cap was the right size, but wouldn't tighten down completely. I tried the locking cap on my 65 C10 and it fit like a glove and tightened down properly on the new 72 tank.