1990 Mazda B2600 Experiencing blue smoke from tail pipe

Just got the cylinder heads done at a machine shop. Relap valves, replace all seals, reseat (1) cylinder and changed all 12 lifters. Assembled heads and started truck. Noticed blue smoke coming out of tail pipe when at idle. Step down on gas pedal and noticed more clouds of blue smoke coming out of tail pipe. Pulled spark plugs out of each cylinder and noticed gas on plugs. Recheck timing mark and saw that it was off by 12 degrees. My cam sprocket is set at the three o' clock position and the crankshaft is at TDC. Even after adjusting the distributor to the 5 degree BTDC or at TDC, there is still blue smoke coming out of the tail pipe when at idle. How can I correct this problem?