Neither was a V6 Mustang. They weren’t special cars or particularly fast. A ‘90s V6 Mustang barely hits 60 in under 10 seconds. For comparison: a ‘97 V6 Camry hit 60 in about 7. Not like modern V6 ones were they are good cars in their own right. The V6/I6 cars were treated as base models since the beginning.
The stock fuel system has supported the engine so far to 400+whp on our dyno with no sign of needing a larger system - including running E85. The V6 even comes with a keyed crank from the factory! Unlike the Hemi's or even the SC'd Hellcat which is odd. Installation is approximately $700. One other option is depending on the Year of your SXT if you get the PCM Unlocked 2015 and above model and a Diablo Tuner from Hemifever with a Tune. you can get a Tune that adjust the throttle response and gain about 20 to 25hp at the Engine Flywheel. A 2011-14 do not need the PCM Unlocked.