I installed a non ecc tank in my '73 and now I’m having some pressure build up in my tank after driving it for awhile. Now there is a valve on the back of the fuel cap that allows air to enter the tank and I was thinking of drilling a small hole in it to allow pressure to escape. Of course I’m open to any other ideas.
Since I installed EFI I had to completely redo the fuel system and remove all the ecc stuff.
