Since you are wanting to run some 1/4 mile and you want to keep the rpm's around 7200, I would have to say to go with the 4.56 instead of the 4.86's.
My car weighs 2650 with me and it has run a best of 8.90@152 and a best 1/8 of 5.69. It has 4.56 gears and 16x33 Goodyears and a BBC. I shift it at 7400 and go through the lights at about 7300-7400 at the 152mph. I run an 1150 dominator.
The second car is a 1967 Camaro (2450lbs) with a SBC. It has run a best 1/8 mile of 5.75, which would have run about 9.05 if they had been running 1/4 mile that night. So far, it has run a 1/4 mile best of 9.14@148 a few weeks ago. It has the 4.56 gears and 14x32 Goodyears. He shifts it at 7400 and it went through the lights at about 7300-7400 at the 148mph. He has the Holley 950HP.
Hope this helps some,
Bill M