[DanEC]

I can't find anything on FE heads with a B9 date code either - I assume they started life as 352/300 HP heads. Not sure how they would have compared to the 1960 352 Hi Po and 390 Hi Po heads. Possibly just some variation in the combustion chamber size. That is an unusual head to end up on a 427. I would suspect someone worked them over and put early 427 size valves in them.

Some of those early 352 and 390 Hi Po motors appear to have put out a surprising amount of power. Hemmings Musclecars published an article on an original 60 Starliner with the 352/360 horsepower motor and 3 speed manual and they dug up some old road test reports of quarter mile times in the high 14s stock. And from learning to drive in a 60s Fairlane (same basic body) I know those were huge and fairly heavy cars. Back then over 1 HP/Cubic Inch displacement was a big deal. And then the next year produced the 390 Hi Po with 3 - 2 bbl Holleys and 401 HP, as far as I can recall that was six years before anyone else used Holleys for tri-power induction.