Smaller pulley on a SSEI

My dad wants to toss a 3.4 inch pulley on his 02 Bonnevile SSEI, i know its simple like 3 bolts to take it off put it back on, but do i need to put on a new belt, or just ajust the tensioner? how much tension is right, how do you adjust it.

it has a automatic belt tensioner but i beleive those pullys r pressed on so u need a pully puller

will the automatic tensioner be able to cope with taht change? if so fantastic. Ill take a look at it tonite, see if its a bolt up or press on. I could of swarn it was a bolt up

15mm to swing the tensioner to lossen belt
pulley puller to pull of 3.8 and press 3.4 back on
replace belt with stock new belt
might have problems with knock though, so he should scan, scan, then scan some more. Maybe get him a 3.5 instead and a DP and it will realy wake up the car

better plugs while your at it

^A step or 2 colder plugs to avoid detonation, agreed?

what is a DP?
so DP, 3.5 incher, Autolite 104’s… will that do? i planned on a K&N filter

zzp tech articles
Read threw all the tech articles. It will give you a good idea on what works and what doesnt.

DP=Down Pipe

ZZP has everything you need for the series II 3800

excellent.