[puts on flame suit]

I have a 99 SSEi with the SLP 3.4 Pulley, tranny cooler and a gutted GM air box and AC Delco filter. I have no problems with KR. I also have several friends with Regals and GTP setup the same and know of no KR problems. Remember GM autorized SLP to install these pulleys on Regals and GTPs and did not affect the warranty, so i doubt that you will see many KR problems.

I had a CAI and removed it because it kept pulling warm air in from the engine and getting KR. I put the GM back on but gutted it first (remove the internal plastic muffler to make it a hallow box) and now it screams, putting down about 10.5-11.5 PSI depending on weather conditions, compared to about 6.5-8psi with the stock 3.8". (using the stock gauge)

I have done some untimed testing on a local road. In the same time it takes my 89 Trans Am with a 5.7L TPI to get to 80, my SSEi can now get to 78 everytime. It was about 73-74 before the 3.4"er.

Also, you are going to want to order a Gatorback that is 1" shorter than the stocker. I believe I have a 71.5" on there. I wil check on lunch. But I also have a post here from last summer that I listed it.

YOU GOT TO RUN PREMIUM WITH THIS SETUP!!!

Im not saying that the exhaust and cat will not help, it definately will, but if you just want to wake up your daily driver for cheap, like I did. This is a good route to go.

Thanks for the additional info karfreek.

A lot also depends on how far you want to go.

I got a 3.5 pulley and got a bigger tensioner pulley as well. By doing so, I didn't need a smaller belt. Also, with the 3.5 you don't need to do anything else, unless you want to. Outside of my smaller 3.5 pulley, all I did was switch my stock ait filter with a K&N filter which causes me to breathe better. The K&N is the same shape and fit of the stock filter but breathes around 30% better.

Note that my way isn't the best high performance way, but is the cheapest since you won't need a CAI or exhaust work,and you will still gain around 25 horses and 40-50 ft. lbs of torque. Not bad at all!

ps. various places sell a 3.5 pulley. I think ZZP does. I got my tensioner pulley from them. Others can chime in on the places who sell a 3.5 SC pulley.