Make a 30* mark. I believe your balancer is 6 3/4" same as the 350, but verify that. What you want to do is make a 30* mark. Circumference = Pi x Diameter. 3.14 X 6.75 =21.20" That 21.20" is 360*. 360/12 =30. 21.20/12 = 1.76". Standing in front of the engine, locate the stock balancer timing mark/slot. Measure CLOCKWISE 1 3/4" and make your 30* mark. Be as precise as possible, and make the mark as thin as possible. If your balancer is not 6.75" in diameter, measure it and proceed as above to figure out the 30* mark.
Update: installed the hei distributor, timed it 32* total.all in at about 2500 rpm .adjusted the vac. advance canister with about 8* (40 degrees total). Fired right up with the new distributor. So I'm assuming the ignitor or coil was bad .just glad to have it fixed. Also timed correct! Thanks again for your input.
Just make sure all the mechanical advance is in at 2500. A very common mistake is to assume that when there is more advance left in the weights. That's why I advise using the very lightest springs to set the total without the VA. You need those weights to swing out to maximum, so you can accurately set the maximum WOT timing. Light springs let you do that at a low enough RPM so you can be sure the timing has maxxed out.
When I had boats people would ask me if I fished, I'd look at them confused and reply " Boats aren't for fishing, they're for partying, docks and rocks are for fishing"
larry, i've been following along with you guys reading , as i'm about to set timing in my 455. got a spring kit with 6 different tensions. are these lightest springs to be left in the distributor after timing is set?
No, the lightest springs are to be used to set the total timing (WITHOUT vacuum advance). The lightest springs allow the weights to swing all the way out at a low RPM. Once you have set the total timing, put springs in that will bring that total in by 2500-3000 RPM. If the springs are too light, it can cause the ignition timing to be unstable because the mechanical timing starts coming in at idle speeds. That can cause the idle speed to drop excessively when the the transmission is placed in Drive. Ideally, you don't want any mechanical timing to start until 1000 RPM. It may take some experimenting and mixing and matching springs to get it right. Once you get that sorted out, then add in the vacuum advance, and tune that if necessary.
By the way Larry. That little 300 runs great.once I figured out what you meant,that is very easy and something I won't forget.
Good! Amazingly simple when you understand it and put it into practice. Guys still struggle with it, but I keep on trying.