Originally Posted by Grouch

50 miles during break in isn't unusual. Engines often use oil when seating the rings. As for the honing or bore procedure, I have no idea. I let the machine shop that did my engines when I was racing, do the work. When I changed the oil at 500 miles, I cut the oil filter open. I put large ceramic magnets on the filter housing while it was breaking in. There really wasn't much ferrous build up inside it. I scrubbed the bores and lifter runs repeatedly until the rags came out clean. Most people don't do that, at least not as often as I did, but I knew what the engine was going to do so it was spotless after machining. That also means there was no honing residue left from the machining.

Keep in mind, Detroit doesn't consider oil usage excessive until it's a quart in less than 800 miles. I changed the oil on that engine every 2500-3000 miles. It didn't use a drop between changes. The quart in 50 miles was the only oil it used.

Keep in mind, you are today. This was 30 years ago. The car is still running although I doubt it is pushed as hard as I did when I built it. I nearly lost my license in it.