Read this thread, even though it is for a shift kit install, it can help you understand the valvebody some and how to get it out, and what to look out for.http://forums.2gnt.com/dcboard.php?az=show_topic&forum=33&topic_id=3201&mesg_id=3201&page=If you have the funds and what some harder/quicker shifts for your A604, get the transgo shift kit.Rebuild FINISHED!VT 2.0 ShortblockBuilt head by ERT, Crower stage 2 camsFidanza adj. cam gearsport matched intake manifoldHigh stall torque converterTransgo Shift kitGST Mufflerinjen short ram intakeGSX dual piston calipers