Hey joe, what pulleys are you going to get?
N1 lightened or underdrive?
how about both? www.vividracing.com
they have a Go Fast Bits pulley set that is lightened and underdriven. it is $220 with the smaller belts.
You'll probably notice more difference with the pullies. They'll help the engine rev faster, and even free up a few horsies. The cat-back may get a few more ponies than the pullies, but you also run the risk of losing too much back-pressure and losing power on the low end or the powerband, while gaining on the top end. I'm not doing anything more than axle-back on mine unless I go with a forced induction system, don't want to lose any of that low-end grunt this engine is so great for!
the Go fast bits pulleys are lightened and atleast one of them is underdriven. 2 light and 1 underdrive. I emailed www.vividracing.com and that is what the guy told me when I got his reply. he said lightened and underdriven. also, they come withe the belts. IMHO, you will get more gains from the Go fast bits pulley set instead of the N1 pulley set. plus, the GFB are $40 dollars cheaper.