Not sure never run a 72 or 75.. did have a 7 though and it was a very good machine for us.. but been told and would believe the 67 is bigger.. unload auger, Rotor size.. shoe.. etc.. ponies.. always could use more... but they let us turn things up a little bit.. (any more?) I'm sure we would also like things to last.. so.. be careful what we ask for...  It's pops machine.. He runs it.. says I can pick something else when he quits.. otherwise.. "no choice in the matter.." 

(I like it also..)