I built a '67 Z28 clone to race in SCCA (see sig). The '67 Z28 had about 12 different final drive ratio options, up to 4.88. Transmission ratios in the only available transmission (close-ratio M21) were 2.2, 1.64, 1.28, 1. With the short gear they were very fast in the quarter mile.
Weight is the big thing here. My '67 optioned how you could option the car then (no smog pump, no heater) but with full interior, totally stock engine/bumpers, etc. but 25lb. front seats and a light battery, is 2950lbs. with a full tank (18+ gallons). More like 2850 with enough to get down the 1/4. Those same mods to a new Z28, even one with no A/C, would still have you around ~3675lbs.
The '67 is my dream car, but isn't something I want to drive regularly, so I'm thinking about a new Camaro... can't decide between 1LE, ZL1, Z28. May end up waiting for the new ATS platform car. The same power and wheel/tire widths in something smaller and 3-500 lbs. lighter would be much much better.