I run a 3.55, 28" tire, 2.66 1st (or whatever 1st is in an 18 spline) in a warm 440.

In your car I would run either a 3.55 or maybe a 3.73 (if I could find one) with a clutch type sure grip and a solid spacer in that 489.

You have a LOT of bottom end, a low first gear and a medium height tire. I think with even a 3.91 you'll find 1st gear to be almost unnecessary.

You also risk ending up with noisier gears with a 3.91 than a 3.55.

Course nobody has asked you about how/where you drive, terrain ect. If your in the flats then definitely a lower numbered gear. if in the mountains then higher.