Nope, the GTX3076 was meant to be a quicker spooling turbo etc etc but it has been tried and tested and is not proving to be that way, it makes good power IF you push big boost.
The GTX3071 has had awesome results if you look up Mick_o then you will see what i mean, perfect example of a well built streeter!
You also have too take the time to check out the HG and Kando threads as well as the RB25 dyno results thread too see that Garrett is only one of the option for you.
I love my 3076 and will be staying with that size even with the upgrades.
I dont have a standard fuel rail so i cant answer that BUT i am pretty sure they do with the addition of a spacer, there is a thread on SAU about it somewhere.... I have 2000's now and they were a b**ch to fit!