Just reading Ed's comments about the car in question: although it's definitely using Z7U components sounds like he's had pistons made and if it's running odd-fire, that'd account for the 6 coil packs (I just assumed immediately that it'd be wasted spark - interested to learn of a management system that will drive 6 ignition coils ). Talk about doing it the hard way though - you could drop in a 73mm even fire crank from any of the naturally aspirated EFI PRVs and make pistons for that, which makes 2849cc and is exactly what Venturi did in the 260 (fully floating gudgeon pins also). Cams are available off-the-shelf for the GTA that'd allow more flow than the stock Z7U jobs which are the limiting factor at 260 at the flywheel.
This has the potential to hit the limit of the transmission.