I posted to a thread last year about the improvements we made to our 3400 series head.     we run the updated deck plates on a 3206, and a 3408 head.  the 3408 we made some modifications to, the 3206 we did not.      the 3408 we ran over 1000 acres of corn through last year, and not once did it plug in a wide variety of conditions and hybrids.    the 3206 had new knives, new gathering chains, a total rebuild, and it still was giving us problems.