Ernie:

I make the clunk line for the right engine a hair shorter than the one for the left. With conventional rotation a twin is easier to fly with the right engine dead than the other way around. So if I go dead engine I'd rather run the r/h engine dry first. But the tanks are big enough that I've not had to test the theory.

If you're running two clunks for defueling ease, do as John said; equal lengths.

Run your engines out of fuel, FAA says you're a fool.

Bill.