The standard backhoe for the 3400/3500 was the 10 foot model 730.poer
C = power class, eg. 3000, 3100, 3400, 3500., 340 etc
U = Utility
1 = Diesel
1 = 8 Speed
K = PTO, probably None
This is tractor only, the loadet would be a Model 340, Backhoe 730
Don't remember so much anymore, been a long...