I don't have any gas smell in my cab unless I happen to spill gas when i'm filling it up.
A tank that is properly installed and not leaking shouldn't stink up the cab at all.
Nothin' finer than puttin' down the road in an old truck, arm out the window, and a big ole cigar hanging out of your mouth.
You may also want to check to see if those vapors you're getting in the cab are not from the engine compartment instead of the fuel tank.
The '52 Dodge I have is horrible for that.
