Just rewire your relays for a ground trigger and connect them to the correct wires on the ECU. Looks like red 33 is for high speed and blue 42 for low speed. If you are running duel fans run one on blue 42 and one on red 33. DomZ can confirm but I think low speed turns on at 180 factory and high speed is 200 factory both can be changed.
http://www.lt1swap.com/2001_PCM_CONN_PINOUT.htm