rear seal leaking maybe

I just received my new short block a couple of days ago and noticing it spots about 10 drops of clear oil.I looked around the passenger valve cover nothing. I looked bebind the intake nothing.I noticed some oil right next to the oil pan in the rear wheres it leaks down on the transmission cooler lines and settles on the bottom of the bell housing. Ifs thats the case wheres its settling would you say its coming from the rear main seals. I no there our some gally plugs behind the engine but some people thinks that highly unlikely. This was done by a reputable man in the thunderbird business. I went and picked this engine up in a couple of states from where I reside and my wifes cousin whos been a senior bus mechanic for 32 years put everything back together again for me. The oil leaks on the outside of the oil pan in the rear on the drivers side. Any input would be appreciated. Would dye mixed with the engine oil pin point where the leak is coming from. Since I got it back I put about 10 miles on the car. I dont no what type of seal was used whether a rope or a rubber seal. Iam taking to a mechanic this coming Monday. This is a 1962 t-bird with a fe390. Thanks Larry

Dye and a blacklight. FEs tend to leak everywhere....but most often at the valve covers and the intake manifold end seals. It always drips from the bellhousing 'cuz that is where gravity and the wind takes it.

Hello Barry. Coming from the valve cover. Installed the best felpro gasket I could find. Problem resolved. Larry

There is an old saying us Ford guys use: "Fords don't leak, they just marking their spot!"

or, "it's ford's new anti-corrosion system."
I've got a few 30-40 year old vehicles without a spec of rust under them.