Here are the headers that will I'm cleaning up and putting back on my Bird. I'll be interested to see how the test comes out (though it won't change what I put on the car).
Bob Hedman made these for this car after Vic Sr. finished the engine. They're slightly different (flanges) than the T-bird headers the Hedman started to produce shortly thereafter. They're very similar to the ones that you can buy at Red's Headers, but these have 1 3/4" primary as opposed to 1 5/8"...neither version has a typical header collector. It's a slip joint/clamped connection.
I've been told that this design doesn't flow as well as the full-length Bird headers available ($$$$) but they are better than the Sanderson headers for the T-bird with straight exit from the engine and smooth transitions...though they do make plug changes even more of a nightmare...
The driver's side still installed before tear down:


And here's the passenger side, removed from the car:


Here are the Red's Headers version:
Todd in Central California...about half way between Fresno and Sacramento
1956 Thunderbird - 1960 F-100 - 1961 Starliner - 1961 Imperial