Re: gaskets/sealers
You should get yourself a copy of the merc manual. If you're like me and have been building cars for a while, but haven't had to do too much work on your boat engines, it will give some good pointers on what is different.
The merc manual is going to tell you to use Quicksilver Perfect Seal everywhere. This is used on the timing cover, fuel pump, water circulating pump and thermostat.
Carb gasket goes on dry. Exhaust manifold gaskets go on dry. Oil pan goes on dry, but you need to put RTV sealer to the joints of the rear seal retainer and the joints of the front cover. That's a small "blob" in each of the four corners and then assemble fairly quickly as you don't want the RTV to set before assembly.
Intake manifold gaskets go on dry, but you need to put Perfect Seal around the water jacket holes and across the front and back valleys. Don't get any sealer in the oil sending hole. If your intake manifold bolt holes in the front and back go into the water jackets of the heads, you'll need to use thread sealer to keep from leaking water.
IMHO, RTV can work fine anywhere there isn't gas around as gas will eat through the RTV. Apply a light coat to one side of the gasket and let get tacky then install. Gasket shellac is for glueing gaskets on when there isn't a good surface in my opinion. If you don't overtorque, you can reuse the gaskets if you have to disassemble sometime soon. Using other sealers that harden make a mess out of cleaning gasket surfaces and ruin the gaskets when it's time to replace something.
That said, I use Perfect Seal on my boat engine anyways.
