Also consider that the built head will give you some extra room to work with the tune as it should be more det resistant than the stocker (with the hotspots left from the less than stellar Mitsu machining).

 

I agree with most everything said thus far. If you are shooting for over 500whp, and the mods you already have, it doesn't seem logical not to get a built head for obvious reasons.

I will say it's possible to get over 550whp with stock bottom and head, but why.. We had a 9 with cams, 35r kit on meth make that much, consistently... never an issue. but he didn't rev over 8K.. ever.. so just do it and know you have the satisfaction and comfort knowing you are good regardless of what you throw at it

 

I vote for get the buschur head, You are already ***** deep and if you dont get it now when the cars all built and finished all your going to keep saying to your friends is " yeah and it would be even crazyer if i had bought the head".