Standalone air/fuel ratio gauges have changed the game when it comes to tuning carbureted engines, with a world of possibilities and pitfalls when using them. We start by comparing five off-the-shelf units, then move on to showing how things like placement, air leaks and even dead cylinders can affect your readings, your tuning decisions, and ultimately your power levels.

Freiburger's 582 big block Chevy is back! And this time we're using it to shoot out 1050, 1250 and 1450 cfm Dominators. When you're flirting in that 1,000-hp range, how much difference do those extra cfms make, and how much does the tune change between them?