Of course crop type and crop yield are a factor. I would think your 350's and 300's would handle 9' sickle cutter with built in crimper (aka haybine or mower conditioner) in most crops and most average yield conditions. If your fields are super dense with super high yields then you could drop down to 7'. (If you have lots of narrow gates to go through then the 7' is also a better choice. Otherwise, I prefer the 9' as they are more plentiful in finding used parts and you will cover more acres faster when mowing and most claim the 9' does not pull much harder than a 7' so you are indirectly more fuel efficient too with with the 9').
FWIW: I have a Hesston 1120 mower conditioner that is 9' cut. I have ran it with a 1950 John Deere model A and a 1951 Farmall h. Either of these tractors is less hp than yours. My owners manual recommends 30 hp as minimum PTO requirement for it. My h is a bit shy of that but it did all my cutting in 3rd gear.
As you already know from using a plain ole sickle cutter, there is a such thing as going too slow and of course too fast with them. While a plain sickle will clog if you go too slow, the haybine reel does help with going slower if absolutely have too because the reel will help clear the sickle and prevent clogging. That all said I always try to keep my speed between 3.0 and 5.0 mph for best cutting with any sickle type cutter.
This post was edited by rankrank1 at 10:40:31 02/23/13 3 times.
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