Besides the grounds, since the starter is out, use a wire wheel on a drill
or a stiff wire brush to clean the mounting surface where the starter goes
into the housing.

Just for convenience sake since the engine is out, pull the axles/CV joints
and re-grease them.

Depending on the age of your water pump, now's a good time to replace that,
too. Its do-able while in the van, but MUCH easier when the engine is out,
and you had to take it off anyway to break down the case.

Another 'easier now then later' item would be the O2 sensor if its old
enough and rusted in the pipe. Its easier to replace when you can put the
pipe in a vise and gently work the O2 sensor out without destroying the pipe
using a wire brush and penetrating oil.

When I had my engine out, I found that was the only time I really could
remove any signs of rust or paint bubbling in the engine compartment. I
taped up everything I didn't want to paint and then cleaned the surfaces
real well with simple green and then used s spray paint can of clear rust
inhibitor.

"My mechanic is doing the work,
but while everything is out, can anyone suggest other things that would be
easier, or should be done at the same time?"

-Good luck,

Gregg
85 Westy, 202k