The project all began in the Bruce McIver era in 1988 when a planned third rail all the way to Port Jefferson got cancelled due to the cost of it would make it cheaper to purchase Bilevel cars along with Dual-Mode Locomotives, so then at that point, the rebuilding of 10 FL9's into FL9AC's took place. 7 went to Metro North, and 3 to LIRR. 10 Prototype C1 (not C3) Bilevel cars were built by Tokyu, and placed into service in 1991 with 2 leased Metra Units that only lasted a week until 4 GP38-2's (251, 259, 266, 269) were modified with special adaptor plugs for the coaches, and 259/266 were equipped with the M1 Pin type couplers. 251/269 could be used, but at that time if those were used, the engines had to turn around at Port Jeff Wye, or at the Montauk Cutoff to be placed on the respective end of the train. Also until the FL9AC's were finally placed into testing service in June, 1994, FA Powercab 608 was modified into a b unit where the cab was cut off, covered over in stainless steel, and had a new Caterpillar sled put into it for HEP.