I have a 92 American Eagle with a 8.3 engine with 77,000 miles which has just started to leak from the rear of the oil pan , I'm ready for an oil change and have seen an additive that suppose...
valve cover gaskets are known to leak and run down the back of the engine ,then it looks like the rear main seal is leaking. these you can tighten your self just snug don,t bare down on them. wipe everything clean and watch for the leak. IF you altered the leak at all? change the gaskets.