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A lot of 74s seem to be like that. Many of the block castings were not up to par---the cylinder walls were prone to rapid, uneven wear, due to impurities in the cast iron or something. I think it had to do with starting engine production at a new plant, and/or the changeover to the 8 bolt crank and metric threaded block. A lot of them were replaced under warranty, but there are still some around, most often in low mileage original cars.
74s also seem to be prone to rapid camshaft wear. Probably the worst variant of the B20 bottom end. The head is a good one though, with hardened seats as original equipment.
I once had an older (6 bolt crank) B20 that used a quart of 10W30 in about 250 miles, 20W50 in about twice that. It ran just fine, had no major leaks, and didn't appear to smoke. I don't remember the compression numbers, but they were on the low end of the normal range, and fairly even. When I bought the car I was told it had a "rebuilt" engine. I never found the exact cause but I suspect it had something to do with that, such as new rings installed in worn glazed bores, or excessive honing combined with wear, resulting in tapered or otherwise uneven cylinder walls. I think this engine was also the one that would blow oil out the vents on the filler cap during long fast highway runs (several hours at 70mph+) indicating a lot of blow-by.
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