What is the largest diameter pulley you can get for a 98-99 SLK230 without having to do anyother internal mods? Where can I find them and how much are they?

Thanks...

 

There's been a ton of discussion on this topic. I would search for 'pulley' and review the existing posts. I don't know the exact diameter but most raise boost to about 9 - 9.5 psi as the Eaton blower delivers pretty hot air above 7.5 psi. There are also interference issues but the post search should answer your questions.