I have searched on here and everyone says pull the vac hose to set initial timing. The problem is, I don't have a vac hose going to my distro. Am I missing something? I have an 86 Elky with stock 305 with computer.

Your advance plugs into the back of the distributor. Unplug that and set away!

Is it a plug or is it a vacuum hose? Because I have a 4 wire electric plug in the back of my distro, not a vacuum hose.

Unplug the 4 wire connector. Set you timing, then re-plug the connector. You will then need to pull the ECM fuse, or disconnect the battery for 30 sec, to clear the SES codes set by unplugging the connector.

tyvm

I guess I should have added that it is a spark advance module, contained inside the distributor. It is also a good time to make your idle adjustments and such. With the timing light hooked up for accurate RPM readings. Check normal, in gear, and in gear with A/C on. Will need to be done under warm engine conditions to keep choke out of the settings.

:beer:

Good idea, thanks.