By the 1970s, the 350 cu in Chevrolet small-block engine was a common—and widely regarded as the most common—hot-rod engine choice.
Chevrolet introduced the 350 as a high-performance option in 1967, first appearing in the Camaro and then spreading across the Chevrolet range. Its 5.7-liter displacement offered a useful balance of power, compact dimensions, plentiful parts, and relatively affordable maintenance.
The engine became especially attractive to hot rodders because Chevrolet produced it in many versions, from mild street engines to powerful Corvette and performance-car variants. Shared dimensions and broad aftermarket support made upgrades, swaps, intake changes, carburetor tuning, and camshaft modifications straightforward.
The alternatives are historically important but do not fit the wording as well. The 283 was an earlier Chevrolet small-block, while the 409 was a larger big-block associated with 1960s performance. The 426 was chiefly a Chrysler big-block designation, not the period’s standard Chevrolet hot-rod answer.