Supposedly running the LLY injectors with the LB7 FICM works, but I'm not sold on it. I'm not sure we won't be hearing that the LLY injectors burned out at some point down the road. Hey, a 12v light bulb will run on 24v for a little while, it just won't have as long a life :dontknow:. Supposedly GM/bosch cut the operating voltage in half on the LLY vs the LB7 (then halved again on the LBZ and newer), Although it's "Unconfirmed". Still, there MUST be SOME reason why LB7's are puking injectors left and right yet LLY and newer rarely go out (at least in the fashon LB7's do).
I'd love to have a chance to tinker with that kind of project myself as I can't think of any reason why the LLY FICM wouldn't work with the LB7 ECM other than some kind of mis-wiring (reversed or incorrect CAN bus for example).