Is the oil running out of the pin hole? If so, then you're oil cooler has failed. They're about $320 to replace. I actually rigged mine up by using some JB weld, a piece of copper wire, a hose clamp, and some silicone adhesive.
First I took the copper wire and hammered it into the small opening using JB weld to ensure it stuck in there. Then I applied a layer of silicone adhesive around the entire oil cooler housing, and finally installed a hoseclamp around it to prevent the copper wire from coming out. It's been like that for about 5 years now with no issues. It's probably not the wisest choice, but at the time I didn't have $300 to buy the new part... I really should get a replacement now that I think about it...
The oil cooler comes off quite easily. It's probably leaking behind the cooler for one of two reasons: you either have bad o-ring gaskets between the cooler and the engine block, or you simply need to tighten the cooler to the engine block. You actually tighten it with the threaded oil filter rod. In the end of that threaded oil filter rod there is a recess for a large allen head to tighten it up.
My suggestion would be to remove the oil filter (drain oil first), use the allen head to remove the oil filter threaded rod, undo the coolant hoses (drain coolant first obviously), and remove and replace the entire oil cooler and gaskets. Late Model Restoration sells them. You also have the option of deleting the oil cooler, though I believe the delete kit is like $150.