ok this may also seem like a silly question but what shape are the NA pistons?....i know mine are flat as i can point a lazer down the bore and i know the turbo pistons are flat at the top

being optimistic i presume the N/A would be pyramid shape like some of the high comp XE engines iver worked on?

the other thing that points towards a turbo engine is that the turbo does not boost until over 2500rpm (cant remember exactly what rpm but its about 65-70mph in fifth)

regards, brian