I have a June 27, 1969 build B2. At the last MCA show it was recommended that I get the correct starter Solenoid. I found 2 different base numbers C9AF-11450-A and C9AF-11450-A Autolite P9DB. Is the C9AF-11450-A the original part number and the Autolite the replacement? Is there any difference between the two?
The flat version your asking about is the "preferred" style by many MCA judges As for numbers are you comparing part numbers (the numbers shown in the MPC or engineering numbers (the number and letters on the part itself)
Looks like the last one you posted - C9AF-11450-A Autolite P9DB- is taken from the metal base of a solenoid since it includes the plant and date code "P9DB"
Believe both versions and earlier and later often used the same part number since they interchange. Because of this not sure if a part number is a reliable
For others there is a comparison of the two styles below for others reading the post
A couple of versions of the C9 flat style
And one of the C7 earlier upright style used during 69 production. No reason to change the engineering number
Earlier thread on the flat C9 style
https://www.concoursmustang.com/forum/index.php?topic=1858.0