It's correct there were 276 Formula 455 HO's made in '72. That was a strike year at the Norwood plant that made all Firebirds so only about 7+ months of production that model year. The transmission breakdowns for '72 are not known so any one of XX figure you see is a guesstimate. Ram Air and Unitized ignition were required options with the 455HO motor, so when you see the X in the 5th digit of the VIN on a '72, it had to have all 3 options of the 455HO, Ram Air and Unitized Ignition. The PHS will only show so much but it's not like a Marti report that will break it down by numbers. That is a very rare car, I'm restoring one similar to it now. The best sight on the internet for info on the Ram Air Formulas is at http://forums.performanceyears.com/forums You should post there about it, very helpful group of owners there. Congrats on the great find, I hope you bought it.

I'm not savvy on my PHS documents, but shouldn't it tell you what the production numbers are?