You'll be fine with a 75 shot and retarded timing. Don't bother with the Zex plugs, I owned them...they sucke. Get yourself some NGK copper plugs, part # BKR7E, and gap them to .030". This is the plug that I run, and most people I know that spray run. Have you made any fuel adjustments for the cams yet? Are you running a chipped ecu?
__________________
2015 Ford Mustang GT Fastback - Ingot Silver - 6M - Performance Package - Gibson Catback, JLT CAI, FR 47lb injectors, BAMA E85 tune, Eibach Sportline, BMR wheel hop kit, UPR oil separator, Steeda shifter bushing/bracket
Team B.O.B.® - Ballaz on a Budget