Hy HawkX66, The main benefit will be the synchronized gears in the SM420. The swap is not a simple one, the SM420 is longer, so the driveshaft will have to be shortened. The bellhousing bolt pattern is different as well so a new bellhousing will be needed, as far as I am aware there is no bellhousing with the SM420 bolt pattern that also has the pedal support boss, one of our members here came up with a fix for that problem, unfortunately I can't remember his name. Your P.T.O. unfortunately will not interchange between the two transmissions, so a new one will have to be found. I am not trying to dissuade you from doing the swap, I'm just trying to inform you what is involved, hope that helps.
Exactly the kind of info I was looking for. Thank you. At least now I see the hurdles if I want the syncros. Seems like the juice won't be worth the squeeze for me.
