Tracking down an oil leak

[402Z]

When I first bought the car it was leaking oil pretty bad. Had the header stud oil leak fixed and it minimized the leak a ton but it is still dripping in one spot. I looked under the car and it is leaking right where the engine meets the transmission. Could it be the rear main? I know Marc says he has never seen a factory installed rear main leak but I am not leaving that possibility out. Let me know what y'all think I'll put a picture of where the oil is landing when it leaks. Thanks.