I cannot comment about the design variation between the old and newer pump.

Regarding the gasket - dry or dressed with sealer.

I looked at your pumps gasket at an online parts seller. This type of design is pretty much std. for front mounted water pumps. I've done a number of these types.

First off, ensure the engine surface is as smooth as a baby's butt. Be careful not to gouge the metal engine surface when cleaning. If room permits, 3M makes some abrasive pads that do a good job of removing old gasket material. These 3M pads were designed to be used with a drill or other rotary power equipment. If there's no room or you lack the equipment, you'll have to resort to elbow grease and medium grade sand paper. I spray on lubricant and sand to help remove the gasket material. Any kind of lube like WD40 or whatever, just something to help soften the old material. The spray on gasket remover products are in my opinion a big disappointment and they are dangerous if the stuff gets in your eyes.

You might be able to use a gasket scraper to get a long stretch of material off, but BE CAREFUL not to gouge the engine surface.

Ok - you've got the engine surface clean and your ready to put on the new pump.

To use gasket sealer or not to use gasket sealer. Which is it? Lots of arguments on this subject.

I would do one of two things.

a. Use no sealant
b. Use a product made by Permatex called "High Tack" in an aersol spray on can.

I would not use any of the goopy stuff that comes in a tube. This stuff can be used in cases where you're using it exclusively to build-a-gasket from this goopy gasket sealer. Sometimes people use this on differential covers where no gasket was ever installed from the get-go at the factory. It's been my experience that using this stuff on water pump gaskets is more likely to cause a leak than prevent one. You'll simply never get it on EVENLY.

The High Tack product is a liquid-like spray on, so you will not have unevenness like you will with gasket sealer. It can help seal surfaces with slight imperfections.

I hang the gasket off of something like a bungee cord, then spray both sides. Let it tack up for 15-20 mins. Lay the pump on a flat surface so that the gasket surface is facing up. I run long bolts up underneath and thru all of the mounting holes on the pump. The idea is to provide "guides" for you to use in order to get the new gasket mounted perfectly over each hole. Once you have each gasket hole over the associated "guide" bolt, you can gently lower the gasket down and on to the pump and everything will line up.

The reason for all of this precaution when mounting the new gasket is the VERY STICKY nature of the High Tack sealant. If you just throw the gasket on the pump, you may have a hard time adjusting its position once on. This stuff STICKS.

High Tack has never failed me.

My 2 cents.

__________________
'91 300-SEL