right off the bat the turbo will not be your issue at 1st. I would start with those injectors! my sixer running a 62mm snail with 60lb injectors (granted im also running a returnless system which needs slightly more fuel then yours).
Yea thats pretty much common knowledge... And as stated It will end up with E85 which needs more volume. I just cant seem to find a Cobra with a 67mm single turbo. Im only using it really to get the kit, bracket and such fitted perfect so the s380r will be an easy swap.