> there will not be anywhere for coolant to "pool". ...
>
>> [Then what causes the problem in the first place if this is hopw they
>> did it at the factory?]

Over time, the rubber gasket and the sealant break down and then,
yes, there will be pooling of the coolant.  But that is after many
miles/years and then there is the phosphate type coolant issue
to be considered in that pooling.  Also, some people think that
sealing both sides of the gasket would ensure a better seal.
Wrong.  Only  the head side gets the goo.  If you seal the groove
side, then expansion/contraction of the gasket will stress and
weaken the weaker side of the gasket, which is the head side.
The gasket is designed such that any movement will occur on
the crankcase side.  So just clean up the lip before assembly.
>
>
>
> I'd also recommend to anyone thinking about pulling heads that they
> remove the engine first rather than try to do the job with the motor
> in the van.  I'll guarantee you that it will be easier in the long
> run.
>
>>Really???  It is that hard doing it with the engine in place?

Of course it can be done in place, but I'd bet that if you are
at the engine age of leaking coolant, most likely you are going
to pull a cylinder out unexpectedly.  The cylinders can be so
stuck to the head that it will take soaking the joint with WD40
and then some mighty blows with a mallet to break loose.
If you accidentally pull a cylinder out, you are in big trouble
because it can be nearly impossible to get back on without
pulling both pistons and re-assembling.