My question is, do you have to be tuned to run these pulleys? Do you need bigger injectors? Or is it just a simple bolt on and go?
Your question as it stands might be a bit generic. Know there are various pulleys, measured by the SC community in percentages. Then consider that there were two variations in stock pulleys...early vs late. Some late model SC owners install an early pulley, see an increase in boost and stop there. An early model SC owner might swap to a 5% pulley and live large. But is that proper? Is there another mod that should be done to make it worthwhile? Is your engine already in poor condition/running on the ragged edge and ready to blow at any moment? etc., etc.
On a stock, early, well running SC, a 5% pulley can frequently be run without other mods, but the point is there are other, different mods that can be done to maximize that single change. And how those mods work together are case/by/case, so one recipe won't fit all examples.
And so it begins.
The question then is...what about your car - is it running well, with no other mods at all, or have you already done the exhaust and....? What is your goal? How do you drive it? What is your budget? What is your skill level if you want to DIY?
Warning - making mods can be a slippery slope, with the risk that there is always one change that leads to another, that leads to another. This usually begins with queries such as yours, so....