Eddie - I just used a best guess for the hole in the brass bypass plug - 3/16. That ought to let the air migrate up if it needs to. The T-bird is "trapped" in the garage at the moment (Oldsmobile in the way) and it hasn't gotten any attemntion lately. The pile of stuff to be modified, assembled or tested is growing.........so the plug is sitting on the air cleaner at storage location "T".
The fuel pump question is a good one - I haven't seen a Carter high capacity fuel pump on a T-bird frame. The Airtex 362 (428) pump I put on my outfit had to have the lower housing unscrewed and "clocked" around to get its pressure port in a good spot for plumbing, This pump very much resembles the Holley 80 gph pump sold for the FE engines - and I'd guess it is close on performance.
Holley seems to be the only outfit that publishes a performance curve for their mechanical fuel pump product. The 80 gallons per hour sounds good - but that number is given at zero backpressure. The curve they publish shows that the 80 gph pump can keep up the required "pounds per horsepower hour" for an engine in the 300-325 hp range - at the kind of pressure you need to keep the carb filled (like 5-1/2 to 6 psi or so).
I've noticed - for whatever reason - the Holley pumps for the Ford application have 1/4 NPT plumbing ports and the chebbie pumps say 3/8 NPT. The parts look interchangable so I would assume that the lower "bowl" of the chebbie pump could be fitted to the FE model of pump. The 3/8 port is attractive if you are running a "full mechanical" system with a suction line back to the tank. Restriction is way worse for performance on the suction side than the pressure side.
Steve Metzger Tucson, Arizona