I understand that 1 & 2 hand rods are rated differently.
What it really boils down to is that the "rule of thumb" for substituting one type line for the other (single hand/spey) I have heard really doesn't seem to apply to this rod.
I have always heard that a line sized for a single hand rod would need to be roughly 3 weights heavier than a switch/spey rating to work with the 2 hand rod.
In my case I bought a rod labeled 5wt, so I figured an 8 wt (WF8F) should be close to matching up with the rod for overhead casts but it wasn't.
When I used the "common cents" method of finding rod weight it came out to 11wt, and an 11wt line did indeed cast well (overhead) on the rod!
So using the same "rule of thumb" but in reverse (single hand weight of 11 minus 3 = 8 wt spey) I'm in hopes an 8wt "switch" line will work.
Guess it's really just a matter of trying the line when it gets here and adjust accordingly if needed. Not trying to be argumentative or difficult, just a bit of frustration in trying to figure this rod out.