Timing Specs for a Chevy Small-Block

Chevrolet's small-block V-8 engine timing specifications depend on the cubic-inch displacement and whether a manual or automatic transmission matches the engine. Small-blocks have cubic-inch displacements of 283, 307, 327 and 350.

The 283

  • The 283-cubic-inch V-8 has the plug gap set at -.35. The point gap is .019. The dwell angle is 31-34. The ignition timing is 4 degrees Before Top Dead Center (BTDC). The engine idle is 500 rpm for standard transmission and 475 rpm for automatics.

Hot Idle Differences

  • The 307 V-8 features spark plugs with a -.35 gap and .019 points gap. The ignition timing is 2 degrees BTDC. The hot idle is 700 rpm with a manual and 600 with an automatic.

BTDC Changes

  • The 327 V-8 specifications are nearly identical to the 283, except for the ignition timing. Model year 1965 250-horsepower 327s have an ignition timing of 4 degrees BTDC, while the 300-horsepower version has an 8-degree BDTC. The 1966 versions have an ignition time of 2 degrees After Top Center (ATC). With the manual transmission, the 327 idles at 475 rpm (with an automatic it idles at 450 rpm).

350's Similar Specs

  • The 350's timing specifications are almost identical to the other small blocks. However, the ignition timing for the 255-horsepower version with manual transmission is at Top Dead Center and 4 degrees BTDC with automatics.