Classic/Antique Car Repair: bb pontiac engine smokes, wt oil, valve seals

Question
Hi..I used to work on sb chevy's in my younger days, now this one has me stumped, I'm looking for fresh ideas, I have a 57 pontiac with a 347 motor.  smoke on start up, not all the time. Valve seals or guides right? Wrong, I had the heads done, new guides, valves and seals. Did a compression test( twice) 148-155 lbs. Book says 155-60 for a new engine. Good vacume test. The cylinders look good with no scratches etc. The engine looks like it was recently rebuilt. I'm thinking broken or stuck rings but it would smoke all the time.Broken, stuck rings should give me low comp and scored cyl walls Any ideas? Could this be unburnt fuel, whitish smoke (not steam)the acc pump is out of adjustment. Thanks roger PS No vac mod line on this engine.

Answer
Roger;
     I know of a few times when heads were done and the wrong seals were used , do you know if the proper seals were put on. And the gas these days will not help the older motors. I would try some hotter plugs and check on the fuel psi. if the white smoke takes a bit of time till its gone than its oil for shure ,, are the valve covers on it vented ,  you have good cyld. comp. but the oil rings can be worn out. try a 30 wt. oil and some STP. it only takes one ring to cause some smoke. or one bad seal-   get back 2 me  ok