Very simply in an EFI port fed motor pressure differential is not used to draw in the fuel as it is a carburetor so a slightly OS TB can not hurt you. Too big of a carb will kill the response down low. Cams, exhaust, ports, valves, timing all will have the major influence on the power band. If the TB is restrictive or undersize it can just hurt you. Kuryakyn has a 95" test mule dyna with a 57mm TB (correct me if I am wrong I believe that is their size) and mild cams TC26G, and their heads, mild compression, making
120+hp with a big fat torque curve over
[email protected] 2500. If a TB is too big it can make tuning a challenge but it will not hurt power or torque.
Flames ON, I am sure.