[TRE Cup]

The tank has to have a vent. You can install one w/o welding (if your tank is already installed in the car and filled with gas)

The center fill neck can be pierced (you can drill a hole on the back side of the neck below the drain pan, if you want it semi hidden) Suggestion- to reduce sparks hitting vapors
a) put a rag in the neck (with enough tail so you can pull it out when done) and stuff it below the drill point.
b) Cover the vents on the drill motor with duct tape . the short term use of the drill with the air vents covered should not damage the drill, but the tape will help keep sparks from igniting vapors
c) make sure you have a really sharp drill bit, coat it with grease.
This will capture the majority of shavings
d) identify what sort of threaded hollow fitting you can install in the hole. Most hardware stores can help with this. Get one that is at least 3/16" i.d. and you can install an outer o- ring on. It should be long enough so it can accomodate the thickness of the tube, the o rings (one on each side of the tube) , and two nuts
e) Install in the tube after drilling
f) Vacuum the remaining debris out before pulling the rag
g) make a round coil loop of the vent hose before routing it to the upper driver corner of the driver side trunk wall, where the oe vent hose attached
h) open beer and relax