You’ve got questions, we’ve got answers. We work with the Summit Racing tech department to help you tackle your auto-related conundrums. In this week’s Mailbag, we’re helping a reader time his engine.


Q: I have a 1956 Chevy with a 300-horsepower 350. It’s hooked up to, and sends power to, a 12-bolt rear axle with 4.11 gears. My question is, how do I time the engine? It has an HEI distributor, and everybody around here has a different way of doing it.

Do I time it at 2,500 rpm with the vacuum advance hooked up, or do I disconnect the vacuum advance and plug it? Would an HEI advance curve kit help any? Do I go to 38 degrees total timing, or should I go farther? I have a good advance timing light, so tools are not the problem.

close up of timing mark and pointer on a vintage chevy small block v8 engine
(Image/Jeff Smith)

A: We would shoot for 34 to 36 degrees total timing at 2,800-3,000 rpm. Set the timing with the vacuum advance hooked up so you can do vacuum and mechanical advances at the same time. To find out what your mechanical advance is, remove the vacuum line from the distributor, plug it, rev the engine, and get a reading off the timing marks on the harmonic damper with the timing light.

As for the advance kit, this would help you optimize the HEI for your particular combination.