Coolant leaking into spark plug wells in my 852 straight 8, non-supercharged.

You might try flattening the thermestat housing neck with 180 paper on a laping plate or some other kind of flat surface. They are just about always not flat.
CORDially Mike

I sometimes have the same problem. Usually it's from the thermostat gasket

I think found the leak. Underneath the neck of the thermostat housing. Running down intake and very difficult to see. A little JB weld and paint until I find a replacement. Tx again for advice.

If you find no leaks, run the engine till hot and watch for leaks.
CORDially Mike

Thanks for your input Curt. Will do.

Thanks for your recommendation. I cleaned off head and wrapped paper towel around base of thermostat and head bolts to check for leaking.
Then I cleaned head and am waiting to see whether drops appear.
I will report what I find.

That is right on the money Mike. I would add, to re-torque the head after the first 12-15 hours of running then again after 40-50 hours of running.

This could be coming from the thermostat housing. But the head can be leaking from the inside out without a crack if this is a original head. This can happened with a small pin prick of a hole that will gradually get worse. Clean every thing up and dry it off and watch for a small drop of coolant seeping out of the head. If this is the case you will need a new head as the corrosion will just get worse. As far as head bolts go I use 50 lbs torque on Alum heads. This should be done in a circular pattern starting in the middle and working toward each end of the head. Before I would try and "reseal" the head bolts I would first made sure the torque is 50 Lbs. For head bolt sealer I use good old Permatex No.2. If you use RTV sealer and retorque the head the RTV has set and when retourquing is done the RTV sealer is torn. The above is one persons opinion. I'm sure there are other opinions with merit as well.
CORDially Mike

I am seeing a small amount of coolant in the wells of #1 and 2 spark plug after sitting.  I do not see a crack in the head, and no obvious leaks in the head bolts. I don’t see any coolant at the hoses or thermostat connection I do see a bit of rust in the pipe plug by the thermostat, and one or two of the washers of the head bolts. Is this a a common problem? 

What is the correct material for the pipe plug and sealant in the head? Is there a sealant or thread sealant for the head bolts that leaks and if so, what is procedure for removing head bolt and resealing? And what is the torque spec?
thanks in advance.
George Lamm