Hello FTE, I've got a few questions for y'all. So here's the situation: My 85' was originally fuel injected (351) and as such had evap (currently missing and the hose is plugged) and an electric in tank fuel pump. I'm going to be getting a new fuel tank as my current one has sprung a leak, but I am not sure what tank to get exactly. The truck is a shortbed so I know I need the 16.5 gallon (side mount) tank. I am trying to decide between getting an earlier tank with the smaller sender inlet (and a matching sender unit) to get rid of the fuel pump wiring and, if possible the evap hole. Also my fuel gauge only works some of the time as it is. I have a few questions: Would there be any way to wire up the fuel gauge to the older sender? Are there any tanks without the hole for the charcoal filter? Do you think going this rout makes sense or should I just go with the correct gas tank an cut the fuel pump wires?

Thanks for the help!

 

Hey, I just did this I was unable to find a sending unit size large! So I ended up getting the small opening fuel tank and the small extremely basic sending unit. It has two wire connections and 1 tube out. One wire to the gauge and 1 to ground. I got both from Spectre, from Advance Auto. Have fun... PS check the Travel stops so the fuel gauge reads correctly if it doesn't have stops you may have to bend the float wire.

 

All of the 80-86 sending units work with the same gauge. And all of the tanks have a vent connections that gets plumbed to the evap canister. If you plug that and run the standard, non vented gas cap, then the pump will pull a vacuum on the tank and quit pumping.

 

Hey , got my vent at LMC.
Just ran a hose off it.

 

I appreciate the advice roadrash and Gary. So I'm thinking I am going to get the older tank with the smaller sender hole and the smaller sender. My current sender has a connecter (I think 4 pin) so I guess I'll look up the wiring diagram to figure out which wires to connect to the new sender. I knew I needed a vented cap, can anyone tell me if this cap is vented or not?

 

ohh filler neck vent, gotcha.

 

There are gas caps that can vent excess pressure to the atmosphere, all the ones I've seen have VENTED stamped into them someplace. But the EPA doesn't like them and they've been pretty much obsolete since the 1970s (and possibly earlier).

 

My web site has the 1981 EVTM with several pages on fuel system wiring. However, your truck is later and the wiring to the tank is different, although the fuel gauge wiring itself may be the same.

 

85 351w was carb from factory(carb till 88ish). in swapping to efi in my 86 351 i found out that the tanks are 85-86 only.mine had the bigger sender hole so all i had to do was get a 86 efi fuelpump hanger and slider it in (just had to add 2 wires for efi pump and mount a stang pump in hanger) 84 down had smaller hole and different line plumbing etc

 

I know those vented caps have been gone since the 70s, but I was under the impression the non evap vehicles had vented caps that had a one way valve that lets air in but not out.