I've decided that since I'm getting the car painted I might as well pull the tank and fresh air box and do it right. I do have some fuel in the tank and just need something to plug the fittings on the bottom so I don't end up with a lake of fire in the garage.

I'm going to replace the lines from the tank to the ones that run through the tunnel but can't remember which size.

I seem to remember either 12mm or 5/16.

I am running carbs so the high pressure FI lines aren't needed.

5/16"
12mm is almost 1/2". I try to use the old German hose clamps again when possible, the US made ones are junk, IMHO.
Good luck, I hope all is well with your project.
Steve

alan, 5/16 (8mm) is what i used. i broke down and bought a 25' box of Gates fi hose. i can use it for FI or carbs. per foot cost was the same as standard carb hose since i bought in *bulk*. next i'm going to put in one of chris' stainless lines so i can forget the center tunnel hassle forever. do you have to run a return line with your 6 fuel pump?

k

Not that I'm aware of. It doesn't have one currently and seems fine.

5/16" is too big. 7mm is correct. The larger of the 2 lines is 9mm, and is the supply line. The smaller is 7mm and is the return. Neither is a "pressure " line in a 1974 chassis, as the pump was originally mounted in the rear. While FI hose is always desirable, even more desirable is the correct diameter! Were I choosing to eliminate one line, I would choose the smaller one, especially since the larger one has a debris screen ("sock") installed in the tank. So what you need is 9mm hose. Odds are the 8mm won't fit. The Cap'n

try a search, busdepot had some nice looking hose clamps, 7 and 9 mm hoses under there

The actual fitting size coming out of my tank (72) is 8 and 10 mm. It's sitting on my bench right now.