Most small-blocks have 4- or -inch-based bores. In this range, everyone says (-inch) or compression rings with or 3mm oil rings are acceptable in nearly every case. Old-school Chevy small-blocks should probably stay to the high side, and the latest new-gen engines to the lower side. And even serious power-adder apps can go thin if the rings are made from steel and nitride-coated.
Acceleration is represented by three familiar numbers: time to 60 mph, time to quarter mile, and passing time, which we define as seconds elapsed accelerating from 45 to 65 mph. That throws a pretty effective net over a car’s high-, low-, and mid-speed acceleration prowess. We’ve expressed braking with four numbers: a panic 60-0-mph stopping distance, pounds of brake-pedal effort while stopping at g, and even the linearity of the brake’s effort when the stopping rate’s increased to a limit-probing g (a shoutout to Loadstar Sensors for their friendly help). Our final stopping-related number is the chassis’ pitch angle at that same stopping rate. A car might stop quickly, but if its pedal effort rises unnaturally or the car’s nose heaves at the pavement with every pedal prod, well, that just ruins the mood.
In the end, we proved that long-tube headers still rule the performance, but in this modern era of tight bucks, tough fits, and emissions regs, short-tube headers are the more practical upgrade.