ATTENTION MECHANICS OF THE BEST TRUCK & MOTOR EVER 1986 22r Heater core plugged so bypassed. Finally overheated one too many times but this time I let it REDLINE.....so blew head gasket. Used Blue Devil sealant and IT WORKED !!!. But my dumb#@% reconnected heater core hoses wrong and as I let it idle I went inside house. 5 minutes later and its steaming with water hissing out new places. %#%%@ Ended up with water in oil this time. I let it sit til end winter 2 months. First thing I did changed oil and filter and plugs and drained radiator(its new)...filled it with distilled water before starting. Was going to use other half bottle sealant and per sealant instructions had to let run to warm up when I noticed ...NO LEAKS A MIRAVLE!àSo my usual 100 mile round trip to fill bed with firewood (no heat)was chilly . WONT stay idle running and ran rough until 20 mph and faster up to 80 mph it purred. LIKE ITS HITTING 3 CYLINDERS UNTIL REVVED UP Got to destination just as it start to overheat. No smoke and no leaks along the way there and back!! INTERNAL HEAD GASKET LEAK! SO WHAT DO I HAVE TO LOSE. MADE TWO ROUNDTRIPS JUST ADDNG ABOUT A GALLON DISTILLED WATER EACH 50 MILES. (Ive made two round trips) NO water in oil still.GOING TO ADD OTHER HALF BOTTLE BLUE DEVIL IN HOPES IT SEALS INNER LEAK. I BOUGHT A $60 SELF CONTAINED BOXED HEATER CORE THAT RUNS OFF MY ENGINE COOLANT LINES WITH DUCTS TO CONNECTTO UNDER DASH SO JUST BYPASSED PLUGGED CORE.EASIER THAN 12 HOURS of tearing dashboard apart ,dozens of nuts bolts & cuss words plus a $ $ spendy heater core. I HAVE RUN THE PISS OUT OF THIS TRUCK for 15 years !! USING DIESEL MOTOR OIL ....THOUGHTS?? GIVE BLUE DEVIL AGAIN.?? Can't afford head resurface.