i read the 1st two pages and skimmed over this one, so if anything i mention has already been discussed disregard it
this is just a brief overview
the ford 90mm maf is good for approx ~450rwhp
when you can reprogram the ecu you don't have to have 'calibrated' meters for specific injectors, you can use anything you wish, a calibrated meter simply 'scales' the airflow by the same percentage as the injector size increase FOR A STOCK TUNE so the vehicle runs about right
with that said the only 2 sensors i recommend are the pro-m 60lb calibrated 85mm or 80mm sensors (good for ~800rwhp) and the 05+ slot style (high flow) sensor available from vmp hpx and the like (good for 3" =900rwhp, 3.5" = 1200rwhp, 4" = 1600rwhp), a factory 05+ ford slot sensor can be had on ebay for $16 from the user massairflow4u or something like that, for a few bucks more you can also get the connector as well so be sure to get that if you go that route, now the factory slot $16 special (non-high flow) is only good for 3" = 240rwhp, 3.5" = 340rwhp, 4" = 430rwhp, so it wouldn't be feasible for most
however, it appears the only difference between the high flow slot and the factory slot is that they burn 2 traces on the board, no one has verified this yet though so if someone wishes to do so post back with your results, the high flow slots are actually stock ford meters they 'recalibrate'
the ford ecu's (excluding the early 80s 4cyl svo's) use high impedance injectors, its useless to use anything other than siemens deka high impedance 80lb injectors, they typically sell for about $365 for a set of 8, be sure they are genuine theres a bunch of fakes that have hit the market recently
a set of 80s in a v8 at 40psi base fuel pressure is good for approx 1000rwhp, it will be less with boost
a single intank walbro 255 l/h pump is good for about 700hp crank
the speed density ford and mass air ford ecu's use the hego's (o2's) on a per bank basis, you can specifically designate which injector you want to assign to each o2 sensor, you can also disable the 2nd o2 sensor if you wish and run only one, especially useful for turbo setups
-decipha