Ariosa, my comments.

Started seeing a drip during winter engine runs, so I started looking of the leak. Replaced the aft hoses on the transmission cooler, but still had a leak. Found a pin hole leak in the aft 40mm freeze plug on the inboard side. Attempted to pop out the plug and replace it while the manifold was on the engine. Could not get the new plug to seat correctly. Removed the manifold, removed all the freeze plugs, hot tanked the unit, and then replaced the plugs. Drilled out a broken exhaust elbow stud. Reassembled and remounted it to the engine. Replaced several other hoses, and tested. No leaks and the engine runs cooler now that the heat exchanger has been cleaned.