Well, its not all that juicy, Dave. However well-documented, anything I get is usually third-hand....its not as though I was there in '68, you know. :-)

All I know is that a former company engineer has gone on record to say that they (whoever that was) selected the lower of several figures produced by dynamometer tests. Further admissions: (a) This practice was not SOP, at the time, plus (b) It was done with the specific intent of understating horsepower.

and what the heck is a "B" curve anyway (I suspect it's an alternate to the "A" curve)?

Exactly. I'm told that typical Ford dyno results of the period included (at least) three output curves, namely the A-, B- and C-curves. These were derived from - duh! - three different methodologies, each accepted by SAE for stated ratings tho' producing dissimilar Bhp figures.

Off-hand, I forget which is which. But, for example, one curve might include the drag from bolt-on accessories, while another did not. And, while everyone involved knew that the B-curve result was always numerically lower than A-curve results, both were equally legitimate. That's how Ford got away with their creative accounting.

Hope that explains it.

Mr F