I have an 85' T/A with a Carbed Chevy 305 in it, had oil blowing back onto passenger front side of motor. Originally thought this to be a ruptured diaphragm in factory fuel pump or possibly a leaking front seal, although this problem started all at once with no previous leaks at all. Replaced fuel pump, no change, replaced timing set & gaskets and seal, again no change. Replaced Mech. pump with an electric pump & blocked off old hole, still blowing oil onto pass. front side of motor. No leakage from intake, valve covers, front seal or timing cover, or oil pan. Car has had Q-jet replaced W/ Edelbrock 600, changed out dist., removed smog pump as well as the cat. Car is running great but can't seem to pinpoint this problem. Any and all replies will be greatly appreciated and I thank you in advance for any assitance in this matter.

 

I had the same problem.
there are 2 bolt holes on the front of the pass side of the block, parallel to the mech fuel pump hole, the oil is coming from the top one. Put a bolt with silicone on the threads and the leak will go away.

I was using 2-3 quarts a day for about a week till my friend with an 87 Monte Carlo pointed out the bolt holes. I think the smog pump bracket was bolted up there, I can't remember since I had my motor all apart for 8 months while I was doing the cam/TPI/ignition/etc.... swap.