For a race car wouldn't be necessary unless some gear limit rule. But for the street it's a good idea for most. Cause 90% of the guy's out there are gonna use 3.23-3.55 for a performance street car even if they go to the strip on the regular. Plus depends on cid, larger cid eg. 440 those gears are more likely closer to correct than say for a 273/318. Take My car 68 valiant came this way when i bought it, 380hp crate engine with 2.96 gears, to even get it into the power band need to get it up to 40 mph then crush it to get any sense of it's power and by then going too fast in town. Even though I plan on swapping gears later I'm going with smaller cam air gap cause it almost never see where peak power is , so I'm willing trade top end power for low end power. I care more about 0-60 mph 1st and 2nd gear performance maybe 80 mph on some roads cause it's not a track car and if that's not enough can always move up in displacement :) If you don't care about which gear you use and not gonna go to a 1/4 mile track, gear it for the 1/8 more inline with intown light to light.
