I have an '89 Saltare with 454 and an oil leak though not nearly as bad as yours. Top of motor is clean and dry with typical valve cover, intake china wall, timing cover, and front main areas dry as well. I have a feeling it's that drain hose on the pan but no room to get at it. My tentative plan is to just pull the motor this winter and inspect for leaks. If it looks like rear main I'll do that and inspect bearings while I'm there but I have a feeling I'll just be cleaning up the motor and replacing the drain hose with a regular oil plug. I use an extractor in the dipstick to change my oil. Mine makes a mess in the bilge but level really hasn't dropped. It's just enough to make a mess when a little water gets in and sloshes around.