You can clean it all pretty good with a seafoam treatment....but at any mileage it is a good mod.
As for the power increase, if the ECM is pulling timing due to the detonation the oil ingestion causes then yes, and MPG should improve. If it is not then don't expect any power increase.
Price is $139 for the single valve can and $39 for the matching breather kit.
$15 S&H.
