RE: Midwest AT-6 Overhaul
O you'll get many opinions on that one,,
I prefer a 3 line system, just for the fact I have seen too many times air trapped in the fill "T" section of the 2 line systems cause sputtering.
If you do go with a 2 line, I recommend you have the fill line come out of the fuse below the tank level so air doesn't get trapped in the fill line.
good luck