The engine actually runs on less fuel than you would call a carbie leak. Thats the whole thing - go start you engine you have running and look directly down the carbie and make note of how much fuel is actually being used.
An engine can be tuned to run pig rich enough to make everything black. When the engine was detonating did you turn it off and never run it there after? You have an engine that runs rich most of the time and under boost detonates. Its not like you have an engine that runs lean all the time and at service time you can check the plugs.

I am not saying fuel leaking is your only demon. Ignition timing could of been crap. Intake temps could of been crap.
But dont think the leaking fuel is nothing.
Fuel evaporates in hot environments.