3:89's get my vote. If you weren't running that 5th overdrive I would say 3:70's, but that 5th will make a lot of difference. I ran 3:70's in my 27 (also a 302 Ford) with no overdrive and it was about perfect with 30 inch rear tires. It would go right down the interstate at 70-80 mph without overrevving. You also need to get that cam into it's operating range.

Of course, what do I know. I'm running 4:30's in the 27 now with no overdrive.

Don