Fuel system with a SBC 350 Swap

Hello guys,

I need you expertise on my conversion. 1980 CJ5, small block 350, Edelbrock Pro Flo 2 EFI, Headers from Novak I think they are Sanderson? to a 3in dual exhaust. Other than the pickup and fuel lines (feed and return) the fuel system remains factory. I am emissions exempt so I removed the vacuum line from the charcoal canister and left the charcoal canister to vent freely under the hood. Problem! When wheeling I am getting pressure building up in the fuel tank. I am sure it s caused by heat from the exhaust. I am trying to eliminate the throwing darts at the problem and missing. My lack of knowledge of the jeep fuel system. If I re-establish the vacuum to the evaporator can will that alleviate the pressure building up in the tank?   Will this collapse the tank?  Everything engine side of the charcoal canister is gone!  Is there another way to vent the tank safely?  

I have vented gas tanks by running a loop up to the top of my cage and then back down below the tank with a small fuel filter on the end (to keep junk from falling in the vent). Looping the vent up to the top of the cage and then back down hopefully will act as a valve to prevent the tank from draining out the vent in the event of a roll-over.

Did you add the return line to the system or was there one present? Did you plug the line that went from the tank to the charcoal canister?  
Verne Simons
Feature Editor
Jp Magazine
verne.simons@jpmagazine.com
www.facebook.com/verne.simons

P.s. I am not Dr. Vern (but I am happy to take credit for his writing!)

New vapor canister. Checked all vent lines including liquid and rollover check valve. Re-established PCV and vacuum to canister. Two test drives and all is well. The monster may not reveal its ugly head till I hit the trail. A couple thoughts. I did consider pulling the fuel pickup and running the return line deeper into the tank. It returns to the top of the tank and after a few cycles through the fuel injection it get hot. Hot fuel spraying into the top of the tank = pressure.   I did think about the loop, but read a form where a guy did that and once wheeling fuel started pouring out the vent.