[jocko]

To install Timing Chain (which will set valve timing):
1.With no chain yet installed, rotate Crank sprocket so dot is at 12 o'clock high.
2. Rotate Cam sprocket so dot is at 6 o'clock low.
3. Carefully remove cam sprocket without rotating the cam, loop new chain over cam sprocket, keep the dot at 6 o'clock, droop chain down below the crank sprocket to engage the chain on the crank sprocket teeth, then gently slide the cam sprocket back onto the cam face without rotating the cam or crank.
4. Re-confirm that the crank sprocket dot is at 12 o'clock and aligned with the cam sprocket dot at 6 o'clock.
5. Install cam sprocket bolts.

To set up Ignition timing after the chain has been installed (i.e. when it's time to install the distributor, etc):
1) Rotate crank until crank sprocket dot is again at 12 o'clock, and via chain which rotates the cam 1/2 as much, the cam sprocket dot is now at 12 o'clock straight up. (if you haven't rotated the engine at all since you installed the timing chain, this will be one full crank revolution, which will result in the cam sprocket dot rotating from 6 o'clock to 12 o'clock).
2) Engine is now set at approx. TDC on #1 Cylinder firing position.
3) Install distributor with rotor pointing roughly at #1 cylinder - front driver's side cylinder. You'll have to rotate the rotor to engage the oil pump tang, so plan on this when you stick it in there. It will make more sense when you do it - but note how much the rotor spins when you try to slide the distributor body straight down into the block - the rotor rotates when the distributor helical gear engages the cam's distributor drive gear) and start with that much offset so that it rotates to pointing at the #1 cylinder distributor cap tower just as the distributor is fully seated against the block (and pointing roughly at the #1 cylinder itself). May take a couple tries.

You are now in the ballpark to start the engine.

You can also set approx. initial timing advance by rotating the crank slightly so the damper timing line is lined up under the desired initial timing setting on the timing tab, ~8 deg BTDC is a good 1st guess, and then rotate the distributor housing slightly (rotor will remain stationary because it's now engaged to the drive gear on the came) so the points are just about to break open pointing at the #1 cylinder distributor tower. Or, on an HEI, just as the rotor is about to engage the #1 cylinder distributor tower, i.e. no points.

I had to re-learn this a few months ago, has been quite a while since I'd done it, and flat out forgot about the difference between the valve and ignition timing being two separate, distinct "things". What's old is new again.