Okay, the saga continues! After some up close inspection, there was indeed some coolant seeping from the head gasket, so those of you that thought this was my issue were dead on. There were just two very tiny dribbles coming from it in the area shown in the pic below.
Seeing as where I live is bitter cold now and also the fact that I don't have anyplace indoors to work on this, I rolled the dice on using K-Seal HD. Well I followed the directions and poured in a 16 ounce bottle which will treat up to 12 gallons, and after letting the truck run and warm up, the coolant temp hit around 195, and hasn't gone above 200 at all since then.... AND my heat never crapped out either and has stayed working! Yeah, yeah... I know, it's a band aid on a bullet hole but for the present, that's what it will be. I've driven around 50-60 miles locally since then and thus far it's holding, so hopefully this will last until springtime and warmer weather and then it's time to dig in and do it right - pull the head. From all I've seen and heard it's nowhere nearly as hairy a job that I thought it is, so I'll drive her with 'kid gloves' until the weather breaks here.
I've seen several threads on doing head gaskets, but nothing really in depth about the job on the M923A2/6CTA. Any pearls of wisdom from out here would be MUCH appreciated!!
