68 Barracuda Fastback 340-s

It has a dual valance certainly looks factory i'll get some pics up later
Also the car has Headrests that came on Formula "S"
Doesn't the "P" in the vin tell it's a 340 car? but not nessasarily a formula S?
If so isn't a 340 car rarer than an formula s car?


How can we tell if it's a Formula S , the fender tag and build sheet tell us but without it how can we tell, anyway for sure to tell.
Please help with info.