all manufacturers tune engines to run rich to protect the engine from its drivers... they don't tune them to run stupid rich like 9:1 however they are tuned pretty rich GTST's for example run between 10:1 to 11:1 (can't remember the exact figure) up the boost on a GTST and you change the AF ratio automatically.
by leaning out the engine we don't mean run at 14:1 on a dyno... we would most likely tune using a VAFC to something like 12.5:1 or there abouts so that when its on the road the AF ratio is about 13:1 (you can not replicate on the road conditions in a dyno room unless you have a wind tunnel). it will then be driven around on the road with a AF meter plugged in to get a real world figures....
the system as far as we can tell the fuel system on the FTO its pretty capable of handling minor changes such as extractors / engine pipes / exhaust / new intake systems... why? cause the OEM ones are pretty damn good to start off with and there's bugger all restriction there...
new intake plenum / manifold we're not sure how well the new ecu will manage it which is why i'm finally getting motivated to install my VAFC

(well using this as an excuse anyway).. the Injectors are definately up to the job...
as we've increased the flow rate by about 10% the whole way into the engine there should be an increase in power and torque ... how much we don't know yet as it hasn't been installed or dyno'd... it could be a huge difference it could be massive it just depends on how much the engine is being starved of 02...we could find that we can pump in a heap more air into the chamber or it could be only a bit... the on car testing will show us this....
however as we have new cams in production... having a intake that allows more air will probably provide better results once the cams are installed. My design thoughts on the cams were to leave the low speed as is (or maybe a minor tweak to improve lowdown torque)... and aggressive changes to the highspeed cams to get as much out of it as we can... allowing more air in and being able to compress it further will create some pretty good results....
unfortunately it looks like we are only going to have GR cams ready for race day so it will be quite interesting to see how the GR compares to the MIVEC... knowing that Rob's suspension (tein v's whiteline springs and kyb shocks) is worth about 0.5-1.0 second advantage around wakefield