<<My favorite mod would have to be removing the rear heater and using
its feed hoses for the auto tranny cooler, thus saving 300-odd dollars
by not having to get those weird tee hoses the factory used.>>

What?

I just replaced all of my coolant hoses, and I skipped buying the large
dollar rear heater hoses.

Why?

Simple.

They aren't needed.

the only thing holding you back from using std.5/8's heater hose to the
rear heater is the T fittings are 5/8's, 1/2 to the heater.

The 5/8's hose clamped down fine at the heater valve, good and tight.

The only thing that is needed to be changed it the T fitting's under the
Van, 5/8''s to 5/8's.

A $1.50 part.