I plan on doing this as well just not sure which line it goes on???
I looked at my old reservoir and one barb looks like 3/8 and the other looks like 1/2.
Not sure which line is which(supply or return).
I think the 3/8 is return...??? 1/2 would be supply...?
Let us know Pat how you installed yours.
Yes big is supply and small is return.