Matt- I can't speak for FAST that is where you might need to contact them directly..

As for injector placement - most of the books discuss the correct placement for injector location plus the also lead to why port injection with long runner approach works.
It's the manner of getting the fuel into the cylinder with good atomization.

The NASCAR ruling is the understanding of attempting to get exact fuel delivery into each cylinder - hence the 4 pattern camshaft was developed by Comp Cams - but this theory in of itself describes the better location other than direct on top of the port..

At this point I need to step back.. I've asked for knowledge of Turbo and the brands and individuals experience from customer service to sizing.. However this thread seems to be going into engine builders theory and beliefs - when it comes to N/A (carbed or injected) I've been around the block enough to know that there are so many different beliefs that this isn't going much anywhere in what I was asking for help..

Matt - I think you are really a nice guy but this is off topic where I need help.. Guess it's time to move onto another forum for the answer concerning turbos and rear mounts..