[Jeff Lee]

As the engine specs changed over the years (cam primarily), I saw improvements going from 5.13 to 4.88 in D/S. I had the 4.88's in when I converted the engine (just the engine) to SS/H. I went faster when I later placed the 5.13's back in the car (I only run a 29.5" slick). I'm now placing 5.38's in the car but am going to a slightly larger tire. You just need to do the math on gears to the RPM your engine works best at. Heck, there are 455 pontiac's that are fast, really fast and only run a 3.73 gear in D/SA. I know turbo cars that have 3.90 gears. So, sorry, it all depends!
A general rule of thumb on a stick is 1st gear x rear gear should be around 15.00. Try that and see if that helps. But do the math!