Another newcomer in 1984 was the introduction of an Automatic Over Drive (AOD) Transmission. This combination could only be purchased with a 302 utilizing a Throttle Body Fuel Injection (TBI) system, also called Central Fuel Injection(CFI). The optional 165 horsepower (123 kW) 5.0L engine with CFI and the 4-speed AOD transmission package was offered with a 3.27:1 axle ratio. The 4V version carried over from 1983 was available only with a T-5 manual transmission. The 4V 5-speed was available with a 3.08:1 axle ratio. The 20th Anniversary Edition GT350's were produced during 35 days of production. The entire production is believed to have been done in 35 batches starting March 5, 1984 and ending in April 1984, there was one final Anniversary Mustang Convertible (TBI/CFI Automatic) Produced on June 12, 1984.