65 Saddle Tanks

[BigDan3131]

Since I already have two of these tanks and I found out today they hold about 15 gallons each. I plan to remove them from the stock location, clean them and rhino them and then relocate them inside the bed behind the tires.

Now what I would like to know is, how big of a line should I use as a balance tube? I will still have two filler necks, one on each side thru the top rail of the bed. Rather than having a switch that can fail, joining them together to make one 30 gallon tank will work just fine. I was thinking -20 should be big enough run under the bed. I will then run two -10 lines from the tanks to the filter and so on.