318 #302 head timing question

I'm running a 195° in mine with an aluminum radiator. Gets to operating temp like it should and stays there.

Should work for yours, seeing as how you've got a very similar engine.

The initial timing set with vacuum at 18 is a good starting point, but you really should check total timing with a dial back light, or some timing tape on your balancer to show you what you are getting at.

Did you try dialing the timing back from starter kickback condition? That's really the best way to do it. Advance it until you can hear a difference when you start the engine and trim it back 2° or until it doesn't change how the starter sounds when cranking.