Ok, for ****s and giggles I did a little research into the turbo you're asking about. Here are the specs
Compressor:
Size: Inlet = 4 3/16"
Inducer = 68.7MM
Exducer = 97.8 MM
Trim = 69,A/R = 0.66
Intake (ID / OD) = 2.25" / 3.25"
Turbine:
Outlet = 4"
Turbo flange = T4
Downpipe flange = 3.5" V-band
Inducer = 87.4 MM
Exducer = 77 MM
Trim = 92
A/R = 1.05
I'm sure that you can switch out the exhaust housing for differing A/Rs. The general consensus, to my surprise, is that they actually don't have the typical issues that china turbos do. Several people have had good luck with them.
That said, this is a big turbo for a stock 5.0. So, it will likely be lazy/unresponsive until you get into the upper RPMs. Something like an MP-T70 will spool faster and be more suitable for a low c.i. low rpm motor like a stock-blocked 5.0.
Anyway, it doesn't look quite as bad as I expected. Check this thread out. I didn't read everything, but started on page 16 and read it through. Looks like it's been tested and is working in most applications.
Some info on gt45 y2004k china turbo.(new pics)
At the power level you're looking for you should be perfectly fine with 42lbs/hr injectors. Beyond the range of what 42s will support you're going to be looking at a more expensive fuel system (rails, lines, low-impedence drivers/standalone, etc...) Plus, guys push those injectors over 500rwhp where you're going to be flirting with splitting the block, building a driveline, etc...
Chris
Edit: I thought you might appreciate this: