"Actual Match Race" 1969 440 'Cuda vs 1973 Firebird Formula 'SD-455'

The info you give on how restrictive the Cuda manifolds is incorrect. I remember one of the magazines did a dyno test of a 69 440 Dart. They concluded that the manifolds didn't hold it back at all and also determined that the engine put down more power that what it was rated for. But not by much. I want to say it was Mopar Muscle. It's been so long ago I don't remember. I do know this. The 69 manifolds are considered the best of the A body HP manifolds. That said, there's dyno proof right on this forum that there is not a lick of difference between stock and HP manifolds.