I have owned a '87 with a #14 head, so I know how you must be watchful of the temp.

I can't advise you on whether or not you have a head problem, although it sounds as if you do not. Gasket is another issue & others will respond on that subject; but it does sound like you may have a problem. Like I said, others will respond on this.

I have never heard of a #10 head. Most guys update to a #18 or higher head when that is needed - I am not aware of other #s between the #14 & #18. If it was my car, I would replace the water pump & then drive it to see if that solves at least some of the coolant leakage (keeping a hawk-eye on the temp). If it does, I would just leave it alone until you see positive signs of head or gasket trouble. With the mileage you stated you very well may have a gasket problem, but I would want more solid evidence before I went to all the trouble to pull the head.

Merry Christmas!

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1987 300DT
2002 Ford F-250 7.3 Crew Cab Short Bed