We have some customers who have tried to plant 7.5" twin rows on our Dawn Pluribus 8" wide strips. Depending on the terrain etc it can be really hard to keep one of those rows from drifting off of the strip.

As SCMN06 and other research points out, yields really deteriorate if you are off of any manufacturer's strip, even a couple inches. 

I would personally question whether 7-8" wide twin rows on 8-10" wide strips is worth the effort. If we start trying to make a say 12" wide strip for 8" Twin rows, you might as well do full width tillage. jmho.

Jim at Dawn