What would be the better gear ratio for a 70 Nova 10-bolt running 1/8th miles?

How tall of a rear tire do you run? If you're on a 26 inch tire try moving up to a 29 inch tire. (borrow a set) or otherwise move up 1-2 inches from your current size. If it turns the RPM you want with 3" more tire you're at the equivalent of your current setup but switched to a 4.56, 2" more tire would be equal to swapping in a 4.88, and 4" would be close to a 4.27, 5" would be close to a 4.11.

It's much easier to change tire size than gears in most cases, you may not have enough room to go up much, but if the clearance is there I would go this route long before swapping the gears and hoping it works like you want. A taller tire will also give you more contact patch, therefore more traction.

Seems to me you have decided on your combination!

Why don't you calculate/estimate what rpm you're going to be at the end of the 1/8th, with the 4.56 gears? You should be focusing on maximizing the utilization of your powerband given the length of the race - you know your engine's power curve, your stall speed, and your rear ratio (accounting for tire size as well). From there, it all becomes and exercise in math.

Your choice sounds fair enough with the 4.56, I've never messed with 1/8th much so I wouldn't really know.

But for some better advice, I would ask questions like that in a true racing forum. You won't get a ton of good information at yahoo answers...

find a 1967 pontiac gto and 411 gears for the 1/8 th of a mile make sure its a 10 bolt possy

well never run 1/8 mile track, but my buddy dose and he runs 4.56 gears in his car and seems to have plenty of gear on the big end.