ok guys
I got the 3.4 pulley from PULLEY BOYS and the puller is on the way.
next is either and K&N cold air or exhaust.
what would you do?

p.s off topic but... what other (if any) motor will fit my 05 S/C monte carlo?

 

It is recommended you do both BEFORE the pulley

 

Don't even THINK about putting that pulley on UNTIL you have done several things.
CAI
180 t'stat
colder plugs
u-bend delete pipe or downpipe with hi flow cat'

Those 4 are THE bare minimums before installing a 3.5" pulley, and then a tune.
You are pushing it with the 3.4 pulley and no mods. You're gonna have problems, like chipped pistons.