I got a 3/8" flare sut off valve today from the plumbing section of the hardware store for $7. The ID necks down at the valve. So, I drilled the ID out to 3/8" by hand all the way through. I had to bevel the inside cuts so that there were no burrs sticking out. You can't clamp the shut off in a vise because it will bend easily. It is made out of brass. Once I got it together, I use my vacuum/pressure guage to check for leaks. Sure enough it leaked. There is a set screw on the handle of the valve. It has a spring and a washer that puts the tension on the tapered valve to seal it against itself. By adding an extra washer, I was able to increase the spring pressure much like we do on valvesprings. That sealed it to 25 psi. without leaks. The valve is a little tight, but it works. There is no real good way to support the valve. I used 3/8" aluminum line in the flare fittings because it is so easy to work with. Steel may work better. I am going to support the valve either by the flare nuts, or on the fuel line as close to the flare nuts as possible. I just put my subframe connectors on. The connectors leave a good path to support your fuel line. I am going to mount the fuel shut off somewhere in there. My whole theory on this is to have a way to keep people from stealing my Camaro. I have so much time, money, labor, and reasearch into this thing, it would absolutely be devastating to loose it. I have done the electrical cut off before. Thiefs know how to bypass that. Same thing with removing the coil wire or rotor. They will always look for a kill switch. What they hopefully won't be ready for is a fuel shut off. When the crooks go to start the car it will run for a while and then suddenly run out of fuel and die. Then they will think it just runs like crap and hopefully abandon it in the middle of the road. I also use a chain and discus lock on my hood. I bolted the chain to the hood side latch and left enough slack so that when the hood is closed, I can just barely get the lock on from the bottom of the nose. The hood closes as normal. One end of the chain goes on one side of the hood latch on the nose, and the other on the other side. The lock rests down low where you can't see it without squating down. The chain is pretty good size. It is big enough that the 3/8" hood bolt can bolt through it. You want to take out as much slack as possible to make it hard to get bolt cutters in. This will hopefully keep passers by from stealing my carb, intake, CD box, etc. At least they will have to realy work at it. This is another reason I am hesitant against getting a fiberglass hood. At least the steel hood will protect from theft a little more. The last thing I use is a lock that goes inbetween the brake pedal and the floor. It is quick and easy, so if I am going anywhere for 20 min. or more I lock it. For you manual trans guys, this works a lot better because you can lock the clutch pedal. Hope this helps someone. I know how much I have into my car. It may be a pain to lean over and turn on and off the switch, lock the pedal lock, lock the hood, etc. But I would rather do all of that then loose my investment.