Get out the planter.  We had a 5400 Soybean special with SI belt meters.  First time I planted an early group IV bean I didn't realize they were bigger beans.. Bought enough for 40 acres.  Planted 40 acres and had enough left to plant 10 acres.  That's also when I learned we were planting beans too thick.

I contacted SI who sent a screen to me and my seed company.  Next year I told them I didn't care what the seed count was, if they didn't fit through the screen I wold not take them.  I was kind of infamous around the company when I refused to accept delivery of 2 tri-axle loads of bulk seed.

2 other things about the 5400.  It will have negative tongue weight when loaded.  I almost got stuck on dry sand one time.  Raised the drill and it took the weight off the rear axles of my 2WD tractor.

The seed tubes are a problem few have solved.  They sag and bunch up the seed.