Rally Pack question

[venom01]

I recently purchased a 65 mustang 'C' code fastback. It came with a Rally Pack but I don't know if this is stock or not. The guy who had the car before me tried to turn it into a gt. Is there some code in the vin or some other way I can tell if this was stock or not? I have a book to decipher the vin but I couldn't find anything about the rally pack. Any help would be greatly appreciated. Thank you.

 

[Kman]

Rally Pacs came either from the factory (a $69 option back in those days) or could be added on as a dealer installed option. K code Mustangs used an 8k rpm tach and all others used a 6k rpm tach. Being an add on option, there is no code to show if is original to the car or was added on some time during the cars life.