Please take a minute and re-read the new rules for 2013 we have 3 divisions compared to the 2 we have ran in the past 20+ years we added a class for thoes "in between" tractors
We have our traditional "Farm Stock" Class that we have had forever the only change is that the hitch height has been reduced to 16" we hear you on the keeping the cost low that is why this class was left mostly unchanged.
The "Farm +" Class for those tractors similar to your stroker 450 some work done but not a full out machine with wheelie bars and the cut tires limited by speed and RPM's
And our "Modified Antique" that is full cut 20% rpm's run what you brung and hope you brung enough
If you are concerned that the loss of 2" in height will limit your success in the "farm" class please remember that everyone in the class will have the same challenges
On a side note I too run an M that was stuck it sounds like yours is healthy and hope to see you out this spring