Firstly to advise putting a head back on an engine to do a compression test, when the engine is out of the car is some crazy talk. For an engine to arbitrarily just start smoking is no where near cut and died as throwing a new set of heads back on and reinstalling the engine to see if it stops.
If it were me, I'd put a head back on and leak it,..but that process seems way too complicated to even go into for the OP to understand, so I'd advise the next best thing:
The damage is done, the engine is out,..may as well take that thing to a machine shop and have them mic the bores, and ck the heads while they're at it.
A smoking engine could be a number of things, including worn valve seals,or guides,..but they typically smoke while idling, or decellerating. An engine w/a broken, or worn out piston ring will smoke while accelerating.
I'm not a fan of one line posts....seems it takes forever to get to the bottom of something. More info is the only way you'll get a solution to your problem.
P.S. The Surgeon General has determined that the frequent use of spell/grammar check can be good for you.