isumatt if i were you i would stay with your old head for now. they have problems with the 3400 series heads i know that from experience.caseih are going to be doing a 45 hour update on the 3400 heads.that is because they know they have trouble the problem with the new one is they made the stalk rolls longer and went back to bearing on the end and it is flexing causing the knives to move apart.as far as the head angle they are the same. we have worked with case the last two years on trying to fix problems. they have put rods between rows to try to stiffen them up bolted heavy angle on out side rows. believe me i am not just making this stuff up. we had to use a 2200 series head just to finish up this year. until they get problem solved i would stay with what you have. i know some farmers machines run flawless but caseih would not be having this big update if they did not have problems.if you think you have feeding and head loss now don't buy a new one till they get it fixed. i am sure they will solve problems and make it right with customers but i just think they did not do enough testing before they released the 3400 heads. well good luck in what ever you go with