Nice idea, but not stock looking (important to me), and the factory didn't do this, so why should I need to, to get a silky-smooth result? My 64 with 70K miles on it (admittedly fully broken-in) ran smoother than this.

Also, if I recall didn't you go with a reground cam? If it has much more overlap/intake duration than stock you will have a lot of trouble getting a stock-like idle.

Points are bad for smoothness too, because the timing jumps around a little. Converting to electronic ignition would be the first thing I would do (and have done on every slant I've owned).

The extended tip spark plugs (drool tube head) helps a bit with the smoothness.

You need a piston stop tool and some white out.

How to:

(1) get piston stop tool. Make one from a spark plug or spend $12 and BUY THIS ONE
(2) Pull the #1 spark plug
(3) install the stop tool
(4) rotate the crankshaft clockwise until the crank won't turn any more.
(5) make a mark on the vibration damper at TDC with the white out
(6) rotate the crankshaft counterclockwise until it won't turn any more
(7) make a mark at TDC on the vibration damper
(8 ) remove spark plug tool
(9) reinstall #1 sparkplug
(10) measure the distance (the short way) between the two marks you just made on the vibration damper. If the factory mark is still accurate, then it should be equidistant from each of the marks you just made. If the factory mark is not equidistant from the two marks then you will need to make a new mark showing true TDC. True TDC is at the midpoint between the two marks.

That's it! I have checked several dampers this way and found that even newly manufactured ones can actually be off by several degrees.

Why break down the engine and why sacrifice a smooth idle? plug the vacuum advance hose, loosen the distributor hold down bolt and give it a slight twist to 10 degrees on your timing light and lock it down. Takes less then 3 minutes to do.

The more initial you run the smoother it idles.

On your video you asked how?

Reed's instructions are very good and it is important to establish a baseline. It is important to eliminate the variables......

Set your timing to the correct setting using the new mark you made rather than the one cast into the damper. From that point forward you disregard the factory timing mark in the damper and base your timing on the mark you made by measuring.

You would only need to pull the distributor if the distributor was currently at the end of the adjustment slot in the hold down clamp and correcting the timing would require you to turn the distributor further in the direction it is maxed out. And in that case you could try and loosen the second adjusting screw on the bottom of the distributor instead of pulling it.
Yes, adjusting the timing a few degrees can smooth out the idle. Base timing affects the idle speed screw adjustment and the idle mixture screw adjustment. The idle speed screws can change how much of the idle transfer slot is exposed which in turn can affect where you set the idle mixture. As Ted said, you need an accurate baseline to achieve the level of perfection you are seeking. A few degrees can make a big difference.

I'd raise your idle 50 and run it for a while and get it broke in. Re-run the valves, check timing & get HEI ignition on it. It really sounds fine to me now!

Rick

A lot has changed since the 60s, including the formulation of gas and the quality of the parts available for our old engines. Mopar DID use factory heat shields starting in the mid 70s. They are rarely seen today since they were made out of a fiber product that degrades and falls apart over time, but they were used.

There are better spark plugs now, better spark plug wires now, better ignition systems now, etc... Also, don't assume that all slant sixes ran smooth as silk back in the day, either.

Additionally, manufacturing tolerances these days are such that you can have brand new timing components that are fresh out of the box but mis-aligned such that camshafts are put many degrees away from what they are supposed to be. For example, the motor in my brother's 83 Dodge van was built using one of the last old Mopar Performance double roller timing chain sets for the slant six. A few years back I checked the integrity of the timing set and the chain was still nice and tight but when I degreed the timing set I found out that the cam gear was cast putting the cam 8 degrees advanced. This is fine since I wanted it that advanced, but the tolerances can add up. Combine misaligned timing components with a vibration dampener outer ring that has slipped and is no longer showing true TDC and you can wind up with a poor running motor quickly.

If you opt for an aluminum intake as Ted suggests, look or the one-piece cast versions and not the two piece e-beam welded versions. These intakes were available on 60 (and maybe 61) slant six engines and then again available in the mid-80s on trucks and vans. The 80s era units will have an EGR valve that would look out of place on a 60s era slant, but that can be blocked off.

If I were you I would start by verifying that TDC is accurately shown on the vibration damper and adjust your base timing accordingly. Then go and adjust the curb idle speed and mixture accordingly.

Next I would play with the valve lash. Run them a little loose like I suggested- .012 intake and .022 exhaust.

Then I strongly recommend upgrading to HEI ignition with an e-core coil. Many poor idling problems have been cured by upgrading to HEI electronic ignition.

Finally, you may need to go through your carb with a fine toothed comb and fine filament wire to make sure all the passages are clear and the idle circuit is functioning as it should.

You may want to increase the initial timing to 10 degrees so it has a little more time to burn the charge.

Why break down the engine and why sacrifice a smooth idle? plug the vacuum advance hose, loosen the distributor hold down bolt and give it a slight twist to 10 degrees on your timing light and lock it down. Takes less then 3 minutes to do.

Great discussion here. Question, though: can't you have too much timing??? My engine is about 1500 miles post rebuild, and if I set my timing much beyond 2.5 BTDC, it kills power and the engine runs a lot hotter.

I'm just wondering if 10 BTDC is a little much for every application.

Like to give kudos to Reed for his recommendation of the 66792 TDC tool. I just spent the past 30 minutes manually turning an engine that simply NEVER stopped turning.

I suppose about 30 more times might have stopped the crank (15 didn't seem to be enough), but I didn't honestly have the heart to do it.

So the Proform 66792? DON'T BUY IT!

Well, so that sucked pretty badly. Looks like I'll have to fashion something myself.