Using oil issue

Assuming no leaking!

1. Rings not seated properly.
2. Engine not really rebuilt
3. Valve seals / guides

My 175,000 mile ago rebuilt 273 uses about that in 100 to 300 miles

When I first start it I get noticable smoke out the exhaust till it warms up a bit, then I don't see it anymore, but I'm sure it's there.

Check your plugs for signs of burnt oil.