C5AP-7006 is the component ID or engineering number. It was designed in 1965 and 7006 is the component number for the trans
. housing on a Borg Warner FMX. It should be made of cast iron. This trans
has a separate bellhousing like the C4. The C4 has an aluminum trans
The component number 7005 is for the C4 housing. Ford uses the two numbers 7005 and 7006 for transmission housings. The factory exploded views designate the trans
housings on the C4 and C6 as 7005 and the FMX housing, 7006 for some reason. If these numbers conflict, all that I can say is, that's typical with Ford numbers. Confusion abounds!
There is/was a small tag attached to the driver's side servo cover which contains the transmissions ID on the C4 and C6. The FMX has the tag attached to one of the bolts holding the extension housing.
Just because a component was designed in 1965 doesn't mean that that cast in or stamped number won't appear on a later model car. The year will change when there is a modification or redesign done to the component in a different year. The metal tag is the only way to positively ID the transmission.
If you find an ID tag attached to the driver's side of the trans
. and the housing is cast iron, it's an FX or MX Borg Warner unit. These automatic transmissions were not used on Mustangs.