Dave Its a case of same-same, not the same. The big block Loadflite will bolt to your Imperial. Some of the converters are the same as your Imperial. The governor which controls the shift points are differant. As you read this remember that if there was a differant internal part MoPar had a differant part number for that complete unit. The HD torqueflite used in the Imperials from 63-64 ( PN 2464426 ) had many of the same parts as the same equal yeared L/Flite. The same is also true for the Imperial with the transmission with PN 2408006. Rodger & Gabby Colo Spgs