Gary,
I have to tell you, even with Jyrki's links, I had a hard time believing that a Y in a T-Bird could go 200 mph+ in 1957. So, a little research was in order.
As a general rule of thumb, it takes about 700 to 800 hp to make 200 mph with a door slammer. Aerodynamics of course makes a big difference. With the small frontal plane of the BattleBird, I still felt like it would take at least 600 hp to generate that kind of speed. Oh, me of little faith.
After a little google help, I found out that there were four T-Birds prepped for the 1957 Daytona SpeedWeek. Two were in pretty much stock trim and factory power with no mention of "E or "F" code engines. One went 135 and the other went 138. Pretty good I'd say.
The third was a BattleBird and had 430 Lincoln power with no mention of induction. It was driven by Danny Eames and set a record in B Modified Sports at 160.356.
The fourth bird was BattleBird #98 driven by Church Daigh. The Y was stroked to 348 cu. in. and fed by Hilborn fuel injection. There were no speed numbers given with an attempt to run naturally aspirated, but it is said that they added a supercharger and did just what you said.
According to the book "Thunderbird Milestones", by Mike Mueller and a report from the "Classic Thunderbird Club of Chicagoland", the #98 BattleBird did 205 mph on a down leg and broke on the return run and therefore no record was set. As it is at Bonneville, the average of two passes were required within a period of time at Daytona to set a record. And so the speed just became a footnote.
The report said that the addition of the supercharger while staying with the high compression just destroyed the engine. No mention of changing the Hilborn unit or whether it was a blow thru or draw thru system. There was no mention of the brand or type of supercharger either.
Well, that got my thinking up. Let's keep looking (and trying), who knows, perhaps there is or will be even faster Ys.
Charlie Burns Laton, Ca (South of Fresno)
BurnsRacing981@gmail.com