1998 Cadillac Catera Oil leak Issues

Engine Mechanical problem
1998 Cadillac Catera 6 cyl Automatic 100000 miles

Hello Their, I am having a difficult time trying to see where the oil is spilling from my 98 catera. The motor oil which I assume is seen on tray, or bottom base of the engine it is also seen under near the transmission with heavy residue. When the car has been running for about 2 to 4 minutes smoke starts to become present. The smoke seems to be coming from each side(left and right) of the lower midsection of the engine. It is white smoke. I Changed The head gaskets which may seemed to be the issue of smoke present before, but was not the case. I also re checked to see if I might have put the head gaskets on incorrectly but I re-checked and no sign of oil was present which seems like I solved one the issues, but not of the oil being spilt on the ground/smoke visible. The oil spills right on the ground which seems to be coming somewhere from the bottom section of the engine/ transmission as I sated before. A squeezing/spilling/dripping noise from oil falling to the ground is also heard and visible when the car is either in idle or stopped after being run for about 2-3 minutes.