Who's running a s+upercharger on a stock motor?

For a stock 5.0L I would skip the FMU and get 36 or 42lb injectors. You tuner will know what size to go with. I have no FMU and 42's on my 96 Cobra...(4.6L) I know, but it works.

One friend has a 5.0L with 19lbs and an FMU, in tank pump and inline pump, another friend has a 5.0L, 24lbs and an FMU, in-tank pump and inline pump.

Both their cars run just fine, have been running fine since they installed them in 2002.

being a stock engine you could do just fine with the FMU and booster fuel pump on stock injectors.

the more ideal way is to run a large enough injector and fuel pump that can meet the fuel demands of the engine without an FMU or anything. this route a custom tune is in order to ensure accurate AFR and power/drivability etc.

you need to ask yourself, do you plan on upgrading boost or adding more parts for more power? if so, you could just buy a 255 in tank pump and ditch the booster pump. and go ahead and run the FMU and 19s with the stock engine. until you start making more power. then all you will need to do is a simple injector and MAF swap and get a tune.

if you plan to stay stock, install the booster pump and just run the FMU and 19s, will run great that way too.

reason people hate FMUs is they usually make the AFR mix richer than ideal and are unpredictable for tuning.
but in all reality, they work very well and probably the best thing to use with a stock engine. that way you can run the 19s (the factory EEC knows 19s) and the car will run great, so you dont have to get into the mess of fuel problems and crap drivability with bigger injectors and no tune. 9 times out of 10 bigger injectors arent just a bolt on deal. you need to tune for them to get to work properly

I have a 1990 Mustang with the stock bottom end. I have changed the heads ,intake and cam. I am running a inter-cooled procharger P-1sc. The 42 # injectors and a 255 in tank pump works great . I custom chip would make it even better,but it is'nt nessesary. I hade 480 rwhp with a 8 lb pulley. I have since installed a 16# pulley. I also changed to tfs twisted wedge heads. I have not been back to the dyno shop since performing those upgrades. With the 42's the only problem i have noticed is at low rpm driving it loads up with too much fuel. Acustom chip would cure this. With our year cars we have to have a chip burned you cant just hook up a tuner.

I have an HCI setup with a v2 supercharger making 540 rwhp on a stock bootom end and could make more. 42s on my setup is maxxed out I need bigger but 42s would work good on your considering I am betting that you will want more power and eveually upgrade the cam and heads and then you will be glad you bought those 42s MOST DEF IMPORTANT GET A TUNE. if you cant afford one dont get a SC it is critical if you want your motor to last

I wouldnt run an FMU on fears of something happening in there. Running a larger pump and injectors with a custom tune would be the only way I would go. I would go that direction on a stock motor any day, your not going see 500 hp but you might get 350-390 hp from 8lbs which is great.
I think the problem with the stock motor are the damn heads. Im sure there is someone on here that has an s trim or A trim and a stock motor who could give you some power range you would be in

I was running a gt-40 with stock bottom,stock heads. With fmu,24 lbs injectors 70 mm throttle body, 190 walboro fuel pump and 8-10 psi on my paxton 2000.Car ran great.