Furious is giving you some really good advice. No overdrive, then 3.55's or 3.23's. With overdrive, 3.73, 3.91 or 4.10

70 Roadrunner convt. street car 440+6, NOS, 4-spd, SS springs '96 Mustang GT convt. street car '04 4.6 SOHC, NOS, auto, lowered "Officer, that button is for short on-ramps"