You don't need a new pulley. I pulled the studs out of the water pump and bought some allen head bolts to hold the pulley to the water pump more for looks than anything. My fans fit very snugly in the radiator. I made a lower bracket myself that bolts from the bottom of the core support to the bottom of the fans. The top has a tab that will catch under the shroud and as long as the fans are held up high enough by the bottom bracket, it will stay there. I ran a zip tie that's not visible just in case anything failed, it would hold the fans off the engine but haven't had any problems in the last 6 months of use.
I ran the passenger side fan as the primary which comes on with the ignition since there's all that exhaust plumbing on that side and it needs airflow at all times. My secondary is armed when the ignition is turned on and goes to an adjustable thermostat set at 160 degrees. The thermostat is cheap at autozone. Mine is set up so that it has positive at all times and I have a relay for each fan that sends the ground to turn them on. I had to do that because of the way the fans were wired from Ramchargers.
