Please help engine trouble

A fresh rebuild may smoke a lot for a while due to the omount of oil used in assembly.

If you have been trying to start it for a while you could have a build up of oil in the pipe.

Over filling a bottom end with new seals should not cause leakage unless the breather is completly blocked.

You say that is running now, does it run really well?

Play it safe and do a leak down test and a plug chop.