With an A-518 doesn't it downshift out of overdrive when vacuum goes to zero ? If so how do you go 'full-throttle' while in overdrive ?? Will the transmission even go into overdrive while under full throttle ?

'65 Belvedere II - 446-Indy,727 transbrake,Dana 4.56


'38 Plymouth 4Dr - 408SixPack, A518, Dana60 4:10