Yes you pretty much have to do it with RTV to insure a leak free installment.
Its not that you will do a bad job, its that our gaskets suck.
GM used to install them dry from the factory, but with as many came back to the dealers leaking, they posted a service bulletin stating that when they are replaced they must use RTV on them, both sides when reinstalled. Once GM figured out their goof, I seriously doubt they fixed the rest of the W-Bodys pan gaskets before they left the plant. They probably saw dollar signs when each one left the plant for their dealership to fix this f-up.
I have installed the dry in the past on a brand new engine build from scratch, and they never leaked. but from now on, they get RTV regardless, cause changing the pan gasket once the engine is installed is not a whole lot of fun but it is easy money if you have the tools and equipment. Dealerships charge close to $500.00 to do this, and its like $40.00 in parts and the rest is in labor.
My prices are much less than that, and with all the w-bodys out there, fixing these right for friends and family and friends of the family insures that there is always work to be done out there for me.
~F~