A conversion access gearset includes a first bevel gear, which is connected to a wing cross shaft leading from the proprotor drive train path to the second turbine engine. A second bevel gear is connected to a main transmission input shaft, which is adapted for driving the proprotor. A bevel pinion receives power from the turbine engine, and drives both the first bevel gear and the second bevel gear. An input pinion is connected between the turbine engine and the bevel pinion, and several idler gears are connected between the input pinion and the bevel pinion. A helical gear is connected between the several idler gears and the bevel pinion. The main transmission input shaft is connected to a main transmission input pinion, which is located on the main transmission input shaft opposite of the second bevel gear. The main transmission input pinion receives torque from the main transmission input shaft, and a torque-splitting device splits the torque received from the main transmission input pinion. A torque recombining system recombines the split torque from the upper face gear and the lower face gear, before routing of the recombined torque to the proprotor.