why do i ask??? radiator cap off. now pistons are scored?? what does one have to do with the other? hope i didnt lose you??

 

Perhaps you could read the whole story, not just the beginning. I drove the truck 20 miles at 75 mi/hr, pulling a 16' tandem trailer, with the radiator cap off. ALL the water was thrown/boiled out and the engine got hot enough to expand the aluminum pistons and lock them firmly in the cylinders!

Fortunately, the bores were not damaged, nor was the crank, so rebuilding was not a big deal. Cylinder wear was .002 max and crank almost none, so all stock parts worked fine. Of course I got a full valve job too. All the wires and hoses made it a lot more trouble than when I did my '82 some years back, but mostly straightforward. The worst was fearing I'd forget something.

I don't know the history of the truck, but it was in Alaska for some time and maybe that's where the frame got a coat of rust. The engine had a fair bit of sludge in it, including in the oil rings, so maybe it's just as well I got it cleaned out. It was running great and is a good puller, has 3.08 and Mazda five speed tranny, so I expect it's my last truck. At 67 I see the light at the end of the tunnel. Unfortunately the light is a train, coming my way.

I hope this clears things up for you.
Wilson