pulley and ecu question

[1999 whitelight]

if i install a 4# pulley what do i have to do to the truck besides install it and the belt. i have a 1999 lightning, i only really know mustangs. and i know that with more boost you need to take some timing out... so do i have to have a chip or what???? just need some info on it looking to get a pulley but need to know all of the ups and downs with it.:BF:

 

[SpankDog]

if you go with a 4# pulley you should change your plugs, but some say you don't have to. You will notice an increase in power but without a chip/predator whatever you will not get the most power out of it.