eh... its all preference really. Lots of good turbos on the market.... it all depends on how much power you are looking for realistically. I am running a Precision SC61 (.60/.63) and i get full boost right around 5K .... Great midrange Turbo IMHO. Now i know every setup is different but i had no problem putting down 550 whp on 25 psi. And as soon as i get my new WG spring i will be going back to reach my 600 whp goal.