Gas tank pressure
 

I just purched a new locking gas cap for my 69 from ECE. Now I have alot of pressure in my tank, so when I go to take of my cap it almost shoots off. Is this normal because I never had this problem before. Any input out there. Also this tank dose not have charcoal canister or evap return. No smog stuff if that matters.:confused:

Looks like you need a vented cap and the one you have is unvented and relys on the tank having a vent.