from memory...
The first run had no dashes..just the model number
-1 has emmissions updates and reloacted auto-throttle
-2 I forget, very short time this was valid. We never had any -2's
-3 Move PTO switch forward, HST+ now monitors PTO RPM.
None of these varients had a corresponding price increase, however the price of the tractors has climbed substantialy over the last two years that these codes have been used. A -3 is a solid $1500 more than the orginal GL40's, the increase just did not happen with the change in model code.