I checked that and injector duty cycle was only about 70% when the engine hit the wall.

We switched over to a 1050 Dominator and made some pulls. The engine is still really rough down low but smooths out at WOT with the Dominator and sounds pretty healthy. It pulls to 6200 RPM with the Dominator before the lifters start to complain. Power is roughly the same as with EFI but the curves are a little bit smoother.

At this point I think it is probably the intake manifold design and something wrong with the EFI fuel rails. It actually makes good power and the customer should be happy with it for a street engine. It makes enough power to completely destroy tires as well as transmissions and rear ends so it should be good to go. I guess he'll put it in the car and see how it performs. It might work just great once he gets it bolted up to a good converter. I have some ideas on how to fix the fuel rail layout so I'll suggest those. Changing the intake is a big deal in an EFI engine so I doubt he'll want to experiment with that.