Just wondering if this is possible. I want to change the bridge pickup on my Ibanez SR505 from the standard Bartolini pickup to a EMG 40P5 pickup, however, wish to keep all the electronics working as the do now.
It's possible but why do you want to? What are the Barts lacking?

(BTW it'll take some fairly skillful soldering as the EMG will have a quick connect end and, IIRC, Ibanez wiring is all soldered.)
First of all you would need to do some minor routing of cavity since the MK is slightly smaller.

Also EMG pickups hate second generation(05-09) EQB-III preamps as they have slight tendency to short pups preamp.
Damn it! Disable can't use disable to disable Disable's disable because disable's disable has already been disabled by Disable's disable!