1964 Pontiac Bonneville 389 timing

[jrusk1957]

I need some help or advice. I have an old 64 pontiac Bonneville 389 that I just tuned up. Question I have is what to reference for the timing marks. There is a pointer on the timing case and two hash marks on the flywheel. I know timing should be 6 degrees before top dead center but when I plug dist. vacuum hose which mark is correct for that timing?

Thank you in advance

Jim

 

[melsg5]

The tab on the cover doesnt have numbers on it?

 

[jrusk1957]

no, it just has a pointer and flywheel has two lines about an inch apart

 

[melsg5]

After you have adjusted the points dwell angle, with the timing light hooked up, engine running, light aimed at pointer, you will see the two marks on the pulley/damper. The upper mark is 6 degrees before TDC the bottom mark is TDC. Turn the distributor so that the pointer is lined up with the top 6 degree mark.

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[Hotrodjohn71]

Hi guys. are you still on this forum? I have a follow up question and this info seems hard to find.

 

[melsg5]

What is the question?
The original poster hasn't been here in 6 years.

 

[Hotrodjohn71]

Thank you melsg5. My question relating to the discussion is do you set that initial 6 degrees btdc with or without that manifold vac source connected?

 

[melsg5]

It is 6 BTDC with vacuum advance disconnected.

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[Hotrodjohn71]

Thank you.