67 383 4spd originality

Gentlemen,
I am looking at purchasing a drivetrain that is supposed to be originally from a 67 383 S 4spd Barracuda, but Im having some issues perhaps you can help me with. First of all the stamp on the engine says A383, followed underneath by 6 2. The intake is 2205968, heads 516's, Carb 4298, block 2468130. I cannot find any stamped numbers on the transmission, there is no pad on the passenger side like I'm used to seeing. The casting#'s for trans are; C98561H on the main body (may be 67H), C96708H on tail housing, C95664 W on cover. The guy claims it came out of his formula S car he bought in the early 1970s, but the numbers don't seem to jive. Any help is appreciated. Thank You