ok i ENDED UP BUYING ANOTHER EMAXX FOR TEARING DOWN AND ALSO PURCHASED A FASTLANE MACHINE 3905 TO MAYBE USE THE OLD TRANSMISSION WITH THE GEARS MIGHT INVOLVE SOME CUTTING BUT WILL INCLUDE PICS WHEN IT ARRIVES
You should be able to fit the 3906 tranny to the 3905 chassis buy widening the motor mounting area/ hole and drill new mounting holes- only really need 4 for the old tranny rather than 8, just enlarge the hole so the tranny fits, then mark the locations for the mounting screws & drill them with a 4mm drill bit.