I have a 60 something 390, im guessing its between 64-69. I replaced the timing chain a while back, and finally fired up the engine 6 mos later. because i rewired the truck. I now have the engine running, but am at a loss of how to ignition time it, because the harmonic balancer has one set of marks and the crank pulley has another. they are off buy 6 degrees of each other. im not sure which marks to go off of. I know pulleys are more easily interchangable than h balancers.

I have turned the distributor until the motor "sounds" to run its best. Please help.

 

You've got a great era 390. My advice is go out and buy a vacuum gauge and forget the timing light and and timing marks. Most of the old timers I know swear by timing via vacuum gauges and its all I use to. Cheap and easy, give it a whirl, I love mine.

 

what range should my vaccum gauge read? right now at idle, 650rpm, i read 15 and holding very steady.

 

[font size="1" color="#FF0000"]LAST EDITED ON 06-Dec-00 AT 02:08 PM (EST)[/font][p]Holding steady is a great indicator...if it were fluctuating you'd have leaks. You want to shoot for 20...sometimes you have to lower the idle as you up the timing, and vice versa. Oh, and I'd set that idle at at least 750. I actually keep mine at 800 but then I have a 4-speed.

 

So did you ever get that bad-boy running sweet, or what?