John Paul,
Did you broadcast, plant, or drill the sunflowers?
Size 3/4 flowers need different meters. Eagle was the only place I could find the seeds that were big enough to be the same, so keep that in mind. I was traveling a lot through the Dakotas last year and every mycogen dealer I found only had 3's or 4's.
I planted #4 Clearfields this year and they are a tiny seed compared to the #2 that I've done before.
My planter has plates so yes I had to get new plates from Lincoln Ag for the #4. Some corn plates will work with certain sunflowers though.Different plates needed than corn correct? I know very little about machinery...
Sprayed with a version of raptor at 6 leafs (ok results) myself because nobody else wanted to do a washout of the sprayer during prime time when they were backed up because of the wind.