Update for improvements on the 8V 4G64 head - Dropped it off at the machine shop and after some conversation we decided on a few things. Getting some port and chamber work. Both exhaust and intake ports have some pretty large "humps" that are going to get opened up. This appears to be robbing a LOT of performance from these heads. The combustion chambers are also getting enlarged/reshaped.

Also, the intake valve are pretty large already, and probably why it performs so well stock form with a turbo. So I see no benefit from going with an oversized set. Will post an update once it's finished.