I would recommend 91 to 93 octane on it. Though i still run 87 on mine and have been for quite a time. Yes compression is higher (10.52:1 cliffy will correct me im sure of it lol) however i run 87 and every time i run 93 doesnt last long as 87. However its just me i would suggest atleast 89 since the compression bumped up due to the pi swap.
1996 Mustang GT, 17x9 front and 17x10.5 cobra r replica rims, 255/40/17 front 285/40/17 rear at the moment,
o/r x-pipe flow master 40 series dump downs, cai/ram intake, 75mm c&l throttle body and plenum, pi heads and intake swap, msd wires, stock gears, untuned at the moment, no dyno numbers for now.