Close, one of 64 built, one of twelve left known to exist.
UUMMM, wouldn't telling you be like giving the answer to the $64,000 dollar question so you could win? And, wouldn't that be putting me at risk of Collins Double Bitt falling on me? OK, "Rare". Seldom occurring or found, uncommon. "Fish", Barracuda. 1968 Plymouth Formula S, 383, 4 speed, convertible.. The second generation Barracuda's were made 67-69. Officially no big block Formula S's were made in 67. But two 67's with that package have been found. Officially 68 was the first and last year the Big Block Formula S, convertible was offered. They made 64 of them, 24 automatics and 40 4 speeds. In 69 1/2 they started putting 440's in them, but zero were put in Formula S convertibles. The 'Cuda name was first used in the 69 1/2 models, but none were put in convertibles.
Urban legend said, and I repeat it with no knowledge of truth, just because it sounds cool. With out a roof for structural integrity, the big blocks produced enough torque to twist the bodies so bad the windshields would pop out. There should be pics in the readers rides forum. The car has yet to be restored.