I put a very small amount on the oustide (part that goes tight to the timing cover) ring to make sure the thing had a good seal. I think my haynes man. said to use it so I did. since you tap it in pushing it to the rear, if there was to be too much goo on it, the excess would move to outside of the block as that is the = but opposite reaction of the install process. Also RTV is not like oil and gets tacky quick and would have a hard time to "drip" into the oilpan. The important thing would be to clean the surface, and putting lube on the rubber part that contacts the crank.
None on the whole motor??? what about the front/rear lower intake area, or if you used the rubber ends the intersection of were the ends meet the intake gaskets? What about the water passages on the intake gaskets? The water pump, t-stat, and timing cover all call for a bead of sealer, if anything to hold the gaskets inplace. By RTV I mean any gasket sealer like permatex.