Several years back, I overhauled my 0-320 and had the cylinders channel chromed. Unfortunately, I didn't do a good job of breaking in the engine, at least cylinder wise, and the cylinders got glazed. As with you, oil consumption was bad, but not as bad as what you are seeing. Anyway, here's the list of things I did in order to finally get everything working normally, again.
An old timer engine rebuilder on my field suggested that the following procedure sometimes will scrape off the glazing...assumes a CS prop...climb to altitude...shut off engine, but keep prop turning in a slight dive...use the prop control to cycle the prop from coarse to fine pitch several times...turn on mags! and land. The pressure from the prop running the engine causes the rings to scrape with different pressures/angles on the cylinder walls and could possibly correct some of the problem. Note: I actually tried this and it did get better oil use, but I ended up working on the cylinders anyway.
I removed the cylinders to get them rehoned. This basically recreates the cross hatching on the cylinder walls that were there when it was new. (Actually, chrome cylinders may not come with cross hatching, since they electrically charge the cylinder during the plating process to make cracks in the chrome so that they can hold oil for lubrication...some one else can probably provide more accurate information on this than me.) Anyway, I just took my cylinders to a local engine shop (Auto/truck shop, not aircraft) and asked them to hone the cylinders. They just took the appropriate size hone (Which looks like a big bottle brush) and ran it in and out of the cylinder a few times. You could do this your self if you buy the appropriate hone, but it only cost $45 for them to do all the cylinders, while I waited.
Order the correct rings...make sure you have the correct type for chrome cylinders...rings for chromed cylinders are steel while rings for steel cylinders are chromed. Get a gasket set for each cylinder and reassemble.
Break in is really important for chrome cylinders. You must watch the temps and not over heat them, but you can't taxi around before the first takeoff, either. I pushed the plane to the runway, did a quick run up to verify oil pressure and took off using high power settings for the first few hours. If you can just fly around for a couple of hours at 75% for the first flight, that would be great. Lower altitude is better for higher manifold pressure.
ECI has a nice break in guide on their web site.
Chrome cylinders take longer to break in. Some folks say it may take up to 50 hours.
At any rate, I did the above and my oil consumption went way down and settled to about one quart per 10-12 hours, which is good for chrome cylinders.
I'm sure there will be comments on parts of the above, which is fine, but that's how I did it and it worked out for me.
