There's some pretty good information so far.

As far as Dyno results, there a guy over on the FE site that did a bunch of intake comparison testing over on the FE site and I think he tested the Tri-power and a bunch of other intakes. I couldn;t find the results right off, but there somewhere around page 170 and done in the middle of june last year.

http://www.network54.com/Forum/74182/

If I remember correctly most single 4 BBLs flat out performed the Tri-Power intakes.

tyler is correct there is a difference between the T Bird and the 406 Galaxie intake. The 406 intake has the carb bases higher in the rear than the front to level the carbs (and visually make the engine look more level). The intake is also a bit more of a high rise than the T Bird design and made a bit more power. I'm not sure what body your putting the engine in, but depending on the year you may not have the severe engine angle that the 60-64 full size car had and the carbs may sit more level on the T Bird intake than they do on the earlier full size cars. Regardless, it may take a bit of float level changes to in the carbs, but the T Bird intake will work fine in a full size car(even in a 64 Galaxie like I building).

At this point the T Bird intakes are a bit more rare (as there were apparently fewer made) and are a very desirable option on 61-3 Birds, so you might be able to work a swap of some kind for a 406 intake.

As far as carbs, Not sure of the bases used on the Barry Grany units, but if they are the same as Rochesters, the Intake can be modified to accept them (basically redrilling the intake and a bit of port matching if desired.

The easy way (but not cheap) would be to buy the re-pop units listed above .

A final option if your good with carbs would be to build your own like I did for my FE (Rochesters).

http://www.clubhotrod.com/forums/showthread.php?t=26886