Well thanks ,guys. I'll look around for something really flat.I got the
idea you are conveying.50 grit emery cloth,right? 4 sheets. No fine grit??

 I got started today.May have made a mistake. These heads are dirty. They
had lots of yellow stuff on the combustion chamber side. With one head, I
used a wire wheel to clean this off and get a good look . I can say that
Canadian heads are more coroded  :>).Dont know why .I am not God. These are
not bad. Did wire wheeling do damage? I did clean the gasket mating
surface, and I think I can see the marks left by the wheel.Not to bad at
all.I think the sanding will remove any evidence I was there with a
wheel.Still looking for  a flat sanding block.

I cleaned the heads up with my favorite solvent(gas). I may get ambitious
and remove the valves ,myself.I need more tools and this proceedure will
satisfy that demand. Never done this, but I did lap the valves in a 3.5hp
Briggs and Stratton,once. Lots of fun with those keepers. Suction cuping
those valves, and compounding them  was fun,too. Such a sence of
accomplishment to do that, and know the engine is better for it. So , how
do I remove the valves? What tools do I need that are special?Just do it
like in the Bentley? Just a valve spring compressor? Dont mix the parts up.
No sweat.Where do I get lapping compound, local?

I will use a stick of JB Weld, of recent vintage. Stays moist. 2 or 3
passes.Understood. I like Jim's version of cleaning the pitting.Act as a
dentist. I will use a drill and clean out those cavities.

As far as removing aluminum ,other than in the pits, how critical is this
for new gasket mating? I will sand flat, and I expect the aluminum to look
like it is clean, but did I damage anything by wire wheeling? Should I sand
with the notion of removing very very little aluminum ?