He and Protosport based in New Jersey are doing my 993TT 3.8L conversion with KKK K18/24 hybrid turbo's on the OBDII/MAF setup for about 680CHP. Mine will have a complete engine rebuild with upgraded tranny/clutch, suspension with Bilstein HD shocks and H&R springs. They are rigging the system so with a simple change to the manifold intake and re-programming, we can switch to a speed density system with the 993NA-OBDI ECU to get over 700CHP...after I pass emissions inspection next year.

He is definitely a knowledgeable Porsche tuner.
Even on a 997TT, 800+CHP on stock internals sounds like it's "cutting it close."