Hi,
Little water down the carb shouldn't hurt. Just crank it over a few and it will flush it out.
Be sure your replacing the right seal because there are others in there too. When you replace the seal, place a little Anaerobic Gasket sealer on the edge that will be against the engine so you get a real good long lasting seal. Just popping the seal in sometimes just isn't enough. The sealer comes in a tiny blue toothpaste shaped container. It will only dry when it has no contact with air, the opposite of normal sealers. If you can replace any other items under the timing cover, do it when you have the chance. Check your tensioners also. Be extra sure you also place the belt on the sprockets correctly and install distributor right. One of the biggest issues we have in here is folks missing the spot by one cog tooth of the belt. Do it right once and it will reward you.

Welcome to the forum.