Marine fuel tanks are commonly made of aluminum. There are several
places that will do custom tanks with all the proper fittings and testing.

jtaylor wrote:
For gasolene, for an old sports car.

The car is unusual enough that a new tank is not an option, plus I'd like to
have a bigger one, and have interior baffles (original is just a box). The
original is made from sheet steel.

I was thinking aluminium, but then thought that that might crack; stainless,
but then I had to pay huge$ for the stainless liner for our chimney (can 30
feet of 6" pipe really cost over $1000?); plain steel, but it might rust...

Opinions?