Improving a 283

[Willshook]

It's your engine, but I wouldn't. Scoring isn't likely - and it's not fatal - but more likely the bearings are shot or there's low compression.

For an old engine, the best approach is to:

Drain the oil as much as possible and replace the filter, filling the filter with oil.

Replace the oil with a break-in oil, being careful not to over-fill. Pour the oil in over the rocker arms to be sure they're wet

Pull the plugs and squirt a healthy amount of oil in the bores. Wait a day.

See if it'll turn over by hand. If not...it's probably got Issues.

If it turns over easily, remove the distributor and spin up the oil pump...if you can get pressure, and you get oil to all the rocker arms, you're probably in fair shape.

Time it to 12+ BTDC, make sure you're getting gas to the carb and give it a shot.

Oil pressure and compression will tell you a lot more about the engine condition than "cleaning it out", and few oil changes will get rid of most of that gunk - especially with a little SeaFoam solvent in there.

Just my $.02, and worth every penny I'll shut up - good luck!