I have a 2002 bonneville ssei and it only has a magnaflow cat back exhaust, and i want to drop the pulley size but not sure what would be the best. i wont be doing to many mods after the pulley.

thanks for any information

a 3.5" is the lowest you can go without supporting mods

I don't even know if it'* safe to do that. Remember, 2000+ run lean and tend to knock. Where are you located? Perhaps there'* a member close by that can scan your car. But as Steve mentioned, a 3.5" is as low as you should go, but that might give you some knock.

ya i forgot about the lean condition.

with a 3.4 on mine with FWI, auto lite 605'* and a custom tune i still have 3-4* of KR to get out of it.

I went 3.5" and had 4* KR still, that was with a 3" downpipe, modified 1:9 rockers, a FWI, canned tune, and 180* thermostat.

I would suggest starting with a 3.6 unless you plan on doing more supporting mods real soon, and PLEASE get something that will scan for KR or have someone that has a scanner do it for you.