If your running the stock "crimped" tube you can pull a 1/2" lenght outta the crimping...Been there done that...
There are longer ones..I just so happen not to have a clue where...I'd rather stetch the mofo...Im cheap...
If you get some 1/2" flexible copper tubing, you can make your own tube. I had to when I swapped my new engine in a couple months ago. Of course I didn't have much of a choice because I cracked the original tube trying to bend it to fit my intake. I cut the ends off the original tube so it'd seal correctly at both ends. Slip the cut off ends over the copper tube, slip a feril onto the tube, and tighten it down as you would normally once you bend the copper to suit your needs. Total time, about 10 minutes. Total price, like $2.50