The oldest Superduty I have had is a 2002 F250--and all the seats in my '04 350/'07 350 dually''09 450/'10 450 have seemed to be the same seat, just fancier. I think many of the later years will fit, just be aware at some point they changed the seat belt attaching point to where you can't interchange all of them. And some of the older ones had armrests that won't fit with a console in the center.
How long have you had this 350? Maybe the seat is just worn out? How tall are you?
I think there are some aftermarket truck seats, but pretty pricey.
'05 36TK3 Mobile Suites
'10 F450 new to me
'09 F450 Lariat 4x4--died