Big tractor Power is out in the field with a three big ALLIS-CHALMERS tractors as they work on planting soybeans. Watch a 305 hp ALLIS-CHALMERS 4W-305 4wd tractor work on seed bed preparation, a 170 hp ALLIS-CHALMERS 8070 seeding soybeans and a 161 hp ALLIS-CHALMERS 7060 working on trenching the field for improved drainage.