I know it wires into the stock boost control solenoid harness, I dont know where the two wires connect (which color wires on the stock bc solenoid). The two wires coming off the gm solenoid are both white, one has writing on it. which ones do they go into the stock wires

 

The yellow w/ red stripe wire is the 12v signal for the stock solenoid....on the housing of the gm solenoid or plug connector you will see a + sign indicating the positive side.

Been so long since i've installed a gm type, as we use the AEM one now wih all AEM applications, but IIRC polarity doesn't matter.