oil pan gasket leak

I have an 86 mustang GT, with a 5.0 HO, dual sump oil pan. The oil pan gasket is leaking. According to repair manuals, because of the dual sump pan and the miniscule amount of clearance between the oil pan and the frame of the car, I have to pull the engine to replace the gasket. I'm trying to think of an easier way to do it and I don't know if anyone has tried this. Why can I unbolt the oil pan, let it drop the 1/4 inch or so that it will, fit in a 4 piece gasket set and bolt it back up. Is this possible or am I doomed to having to pull the engine?

I don't have any experience with this, but if it were me, I'd try what you're saying before I pulled an engine! Just put a generous amount of permatex on everything.
Good luck.