1989 Toyota Tercel valve seal replace

My '89 tercel 125,000 mi. Was running rough while idling only. I performed a compression test and found #4 cyl. Low compression, burnt exhaust valve. So I pulled the head replaced all 4 exhaust valves, and all valve seals, even intake valve seals. I lapped in exhaust valves, replaced intake valves in original positions. New head gasket of course, torqued head to specs as stated in manual. Car starts and runs smooth but very extreme amount of white smoke from exhaust as if car was in fire and will not stop smoking. Pulled head back off took to toyota shop to have inspected, head checked out good. Put back on with new head gasket same thing. What would be causing severe white smoke. Not losing coolant.