
There are alot of variables but I have a hard time believing it caused a groove in that short of time.
I have two LUV's and my son has one as well. I have 104,000 miles on my '81 and blew the head gasket a couple years ago. Was working 60 hours a week and also going to school full time so I tried a "Mechanic in a bottle" type stuff called MEND TITE and have had no more issues. I have never been a believer in any of that stuff but I have to say it worked. My truck would empty the radiator in about two hours but I have to say it IS still working.
My other LUV has been parked for about a year while I work on it when time allows but has over 150,000 miles on it and as far as I know it's the original head gasket. My sons has over 120,000 miles on it and once again, as far as I know it's the original gasket.