Cougar speed

I have a 1999 cougar 2.5L, and it's bout as slow as my grandmother when it come to racing stock cars:disappoin . What would be the best way to increase the speed. Would it be better to put a 3.0L in it, or have the block and heads worked on the 2.5L? Please Help!:confused:

if your going to have the block worked on, you might as well just swap a 3.0L. Of course, boring out a 2.5L, diminishes the integrity of the block since the sleeves are not really big enough to bore to any significant level. Youll definetely pick up more hp and tq with a 3.0L swap vs pnp heads.