My two bits would be 4.10.
Any more gear , depending on tire , you could be getting on the verge of needing a 3-4 shift before the traps , which I think might negate anything gained in the 60'
This all depending on how much engine you plan on.
4.56 with 26 tires @ 106 MPH = 6400 ( no converter slip)
4.10 with 26 tires @ 106 MPH = 5760 ( no converter slip)
All bench racing of coarse ,
I did however run 4.10 gear, 26 tall tires , 3000 converter when it was an automatic