Adams' Apple said: Greg, have you tried cranking it with the plugs out?
Does the distributor rotor turn when you crank it over?
Does the engine oil smell "funky", or like it is burnt?
Do you have access to a bore scope?
It's possible that one(or more) of the wrist pins has worked loose from a rod, and is scraping on a cylinder wall. Not a good thing, for sure.

I'm thinking hard about what you said about the distributor moving, even tho it is tightened down as tight as the clamp will go. Imma wondering if the dadgum distributor itself hasn't taken a dump. Not the electrical part, but an actual mechanical failure...like the gear melting, or the pin on the gear shearing off...or the teeth themselves wearing off.
IF the dist. shaft itself was really tight down in the hole, it could mash the gear up against the oil pump too tight, and also against the boss in the block.

I'm REALLY hoping this isn't a major engine failure. Normally, if a rod, or crank bearing has taken a doo-doo(hi-teck terminology), the oil will smell bad. It also usually will cause the engine coolant temp to go high.
A rod pin coming out will scrape against the cylinder wall, also normally causing a higher than normal coolant temp, and lottsa metal in the oil.

A jumped timing chain will not normally damage any of the valve train parts, unless you have domed pistons, or a really high-lift cam...or rockers that are adjusted way too tight.

I'd really start checking the distributor....see if the rotor will turn with the engine, and that you cannot turn it(the rotor) by hand....

Fingers crossed....

Alan

 

I picked up a 383 stroker the other night from a friend of mine. It's a low mileage engine with aluminum heads and a mild cam. It's a 2 piece seal block from the 70's. I heard it running on a test stand. Good oil pressure and stabile vacuum. It'll get me back on the road for a low price with a bit more oomph.