Measuring didn't go well. I did find it was 16" from the top of the tube to where it meets the rubber hose. So I'm guessing the tube is about 17.5" long.
If I did cut the tube, I would have held it in place and marked it so it was up about 1/2" from the pan tube. That gives wiggle room for adjustment. Then use a 3" to 4" piece of rubber hose.
Here's a picture of mine. You can see the water pump bolt head where it holds the bracket (a tab welded to the tube):
