Stumbling Slant --what is left??

wrock said
68 Dart with a slant. I noted that the distributor shaft was getting a bit wobbly when I last tried to change the points, so I tried rebushing the distributor I had, failed at that, and replaced the distributor with a used one I had. I might have had a bit of hesitation before this, but now I had real stumble--at idle, under load, all the time.

Check and see if the vacuum advance pod is faulty (can you suck air thru the vacuum advance hose?).

Checked the compression--all six between 90 and 118 PSI.

Low. This motor sounds like a tired pony—as also evidenced by your worn-out distributor.

Interesting: the new plugs with barely 30 minutes of idling on them are showing carbon black. The old plugs that came out were fairly black, too.

Tired motors do this. Suspect you've got a lot of blowby coming into the intake tract via the PCV line, and the oil vapours are crappin' up your plugs. Speaking of the plugs, those ring washers don't belong on 'em in a '63-'74 Slant-6 head; take 'em off the plugs.

Tune-up parts and technique suggestions in this post.