I will answer this one, he dosnt know

The ideal legnth however will be different to the supper 1600 so will be optimised on the dyno I would imagine he will use the s1600 set up as a base to start from.

For outright power 8injector is the way to go.
Run banked injection and turn the back set on around 6ms injector on time (or there abouts), this way you can run the front set to a reasonably high power output with best drivability and switch backs on for power.
Whilst on the dyno he can see at what rpm he gets stand off (if it does) and switch the fronts on more than the rear.
(6r4 was the perfect example for the standoff issue)