i found some things that i know very little about whats your outtake on these.

UNDERDRIVE CRANK
5 ribs - Ecotec Underdrive Crank Pulley - 2.0LNF/2.2/2.4: by Make and Model - Chevrolet - Cobalt - NA Ecotec UDP - Car Performance Parts And Auto Accessories | MRZ Performance

LIGHTWEIGHT ALT PULLY
Lightweight Alternator Pulley - Ecotec 2.0LNF/2.2/2.4 - 5 ribs: by Make and Model - Chevrolet - Cobalt - Ecotec 5rib Alt pulley - Car Performance Parts And Auto Accessories | MRZ Performance

 

No, no and no.

 

They will probably help performance, but is it enough of an effect that you will notice? Probably not, thus probably not worth it. You will definitely have to weigh the cost vs/ performance gained and then you will have your answer.

 

I've always thought about it.. but I've only ever heard bad things about changing pullies on ohc motors.. not quite like the old days of yore.

 

i thought of just getting them for show. and maby i can use my A/C and get same MPG