the 318 is internally balanced,,not needing any weights on the convertor or flex plate,,,and a netural harmonic balancer,,,
the 360 is externally balanced,,,needing balancing on the front of the motor( harmonic balancer) and on the convertor,,either on the convertor or by using a after market flex plate designed to balance a motor using an un balanced convertor,,,
also the magnum motors have a timing mark on the flex plate,for using factory electronics, EFI & computer controlled distributor
