The orginanl model was designed around 2x 50mm brushed EDF units , modern 30mm brushless edf,s would be more than ample and more scale like

This RC model aircraft kit of a Boeing 727 airliner, with a 1150 mm wingspan, is produced by LASER DESIGN SRVICES. The unassembled kit is made of wood and is designed to scale. Perfect for aviation enthusiasts and hobbyists, this kit allows for a hands-on building experience of a classic commercial airliner. , this RC model aircraft kit is sure to provide hours of enjoyment for those looking to fly their own virtual Boeing 727.
There is a detailed build thread on laser design services website