Hey Doug, good to see that you are running again! I agree w/Curtis. With that big tire and 4.56 gear, you're probably pretty close. Personnally, I'd go with a 4.88 with that tire and weight and a small block. I figure you're probably turning 7000-7100rpm at that speed and a 4.88 should push that up to 7400 or so and knock about .03-.04 off the 60'....what is your stall speed with the 434? Cam specs and heads?
You could go with a lower 1st gear in your glide if you don't want to wind it that high. I had a 2.03 in mine with the small block and a 1.98 in it now with the 522......
Johnny