The tubes from the parts stores are easy to bend. The hardest part is getting the right length. They come in 10 in. increments. Like 20-30-40in. There is a 6 or 8in. & a 12 in I think. Sometimes you can get a union & put 2 together. Otherwise get a longer one then nessesary & have it cut & double flared to the right size. They come in 3/16 & 1/4 in. dia.
