Relating to fox 5.0 guys with 8.8"'s, the 3.73 recommendation is probably the most popular. I have 3.55's in one stang and like them. Guys tend to also like 4.10's (3.90s are an option, but they are not a Ford gear).
Now we dont know what your motor is gonna be like - you might be making enough power that lesser gear works great. But you can kinda see the range of gears we like, so you can adapt that to what is available for your 8".
Is that kinda what you were lookin for?