Try test light on tach wire to ground. Or not at all. Just leave the tach wire disconnected from everything. The only thing you haven't changed is the coil. did the distributor come with cap rotor and coil.
Check to see if the PCV valve is clear and clean. small price but can cause build up of crank case pressure and cause oil to be pushed out the gaskets.
I have seen 2 similar problems....... One was the little gasket that the kick-down cable goes through or the housing of the kick down cable itself where it goes into the case was cracked. The other problem was a crack in the torque converter to pump flange. Clean it up real good with brake...
I think that your choke pull-off isn't working. the choke should open about 1/4 inch as soon as the motor fires. If not you are actually giving the motor too much gas. Try opening the choke a little bit as soon as the motor starts.
I hope this helps.