got a 70 lemens with the 350, my 69 firebird the timing was 10 before the 70 is 9 before, I have it at 12 and it seems ok what are you timing yours at? the motor is stock.

Hello,

I have an HEI distributor in a different non Pontiac vehicle with a 350 engine (1979 year engine, 1959 Apache truck) that I can't set time by using a timing light. The timing mark line on the harmonic balancer has slipped off of its factory calibrated location - slipped on the internal rubber damper. Thusly, I must time the engine using measurements of engine vacuum, best steady idle, ease of engine starting and no audio evidence of engine detonation on 87 octane fuel. This engine also has no timing indicator spot welded to the metal timing chain cover. Another complicating factor for me is that when the engine got rebuilt by a previous owner, they put in a camshaft for a recreational vehicle that creates more torque at low RPM and this engine really likes 900-950 for an idle RPM. And I got no cam card with the camshaft specifications.

This is also a gut feeling of proper timing, a casting of some Haitian high priest chicken bones, palm and Tarot card readings and the calling of a seance.

More seriously, I can't do a check of timing with a light and these other more scholarly methods do work but it does take a few more adjustments. With the age of some of these engines and their uncertain rebuild specs, all kinds of things can have happened. In other words, you might have to experiment a little for best operation.

Rick

Almost every engine will benefit for more initial timing at idle. Factory timing numbers at 9 or 10 degrees are just not enough for an engine to idle nice and smooth . More initial timing will let you close the throttle blades more so the carburetor is running properly on the idle circuit.

You do have to watch the total timing with today's crap gasoline and compression with iron heads.