If your car is an "M" code then it came with tri-power. However I do not think that was an option in 1964. There are two different tri-power manifolds. There is the more common one available for passenger cars. The less common manifold is specifically for Thunderbirds. The Thunderbird manifold has less rise to fit under the hood of the thunderbird. the carburetors may be the same, I do not recall. The
part numbers may be for 401 h.p. 390s, 405 h.p. 406s. there may be an over the counter
part number that may vary. It wil possibly end with an A for the passenger cars and with a B for the Thunderbirds. I cannot tell you if the passenger car model will fit on your car. It has been well over 50 years since I worked on a tri-power FE. good luck in your quest. Again a long time ago. The center
carb would likely have a different
part number than the front and rear carburetors. Most 3
carb set-ups have only a choke on the center
carburetor and factory linkage is progressive. The center
carb will also be jetted differently from the end carburetors. I would think that there is an FE group on-line that can tell you more. Another thing that may be on the M code set-up could be a dash-pot to slow the de-accelleration with the automatic.
Any way good luck to you.john