adding horsepower and exausht??

what can i do for added horse power on my 89 4L XJ?

and im also interested in adding exausht..i want something that sounds really good any suggestions?

thanks

first off everybody else is going to tell you to do a search.

But whatever I don't care

I would go with a flomaster 40 series muffler with 2.5" all the way back

got mine about a month ago itssounds nice and gives a little more power. might want to replce your header @ the same time since the factory ones crack. I would have done the header first but I ripped my stock muffler off on a log and had to replace it