Have you downloaded the service manual yet? If not ,it's available under the documentation collection, here on the forum. That will be a great start in learning,the how's an why's of the components of this engine.

 

With an attitude like that you will not get many replies. Using the word please helps a lot.
Use search as the answer is on this forum, posted many times.

 

Go to "Index of Repairs" in SRT6 Engine section is a PDF for S/C pulley install. It will tell you everything you need to know. I just changed mine Monday and I did not need any shims. I installed the ibf steel pulley from Poland.