maybe...
I dont hear of 6.2's and 6.5's blowing head gaskets too often,but its not unheard of either,especially at that age and mileage..it all depends how much prestone got into the crankcase,the bearings will suffer just like any other motor that gets antifreeze in the bottom end..
And if it leaked badly enough it might have damaged an injector tip--diesels don't like water ,usually if any gets in the fuel or combustion chamber it will blow the tip off the injector,or at least damage it enough to it no longer sprays a nice pattern,but drips and leaks instead..not a big deal to change though,or that expensive....
I'd take a long look at the oil dipstick,and see how contaminated the oil is..it will be hard to tell how much antifreeze got in the oil,it always looks like tar in most diesel engines!..but if its watery or milky looking,thats not a good sign..but I've gambled and changed head gaskets on many gas engines that got some in the lower end,and just flushed them out good,and put new oil in,and they lived too.
.some only lasted a week,then started knocking..
.. Depends on how long the bearings got exposed to the antifreeze I guess...
Sounds like a decent truck for the price though,if the body is decent,its probably worth it,even if you had to get a used motor or rebuild the old one comepletely..
