The torsion bars were the same diameter between '65 and '66 Formula S's but they changed the part number and therefor the number on the bar. There were no rear sway bars from the factory on an A-body until the 1976 police cars. !0" drum brakes were the standard for all V8 Barracudas in 1966 with a disc brake option on all models. Also it was the first year for the optional 8 3/4 rear. Usually the 4 speed versions got one but I've seen two "S" 4 speed cars with a 7 1/4 sure grip in them and they were unmolested virgin looking cars so who knows.....maybe they ran out on the assembly line that day and threw in the 7 1/4 to keep the line moving. All the "S" options are bolt-on so there really isn't an easy way to tell a clone on those cars except for the fender tag. If it's missing, the only verifiable way is to send the VIN in to Chrysler Historical and get the data right off the IBM card for that car. If the fender tag has been switched with another car, you can tell by seeing if the shipping order number matches the stampings on the body. Naturally, a build sheet will verify all this info but they can be forged also.
Except for the Valiant emblem on a '65 Formula S, the others are not uncommon. The '65 probably had the emblem installed at a later date by someone who though it was supposed to be there. There again, in my experience, that was not uncommon either.
