[martindc1]

Just got mine back together and it runs like a top. The old pistons were shot because I had several broken rings. Before the rebuild it used over a quart of oil per 100 miles but still ran ok. I can only guess that the engine had around 128k on it by the odometer, but it probably had a lot more use than the odometer shows because the truck has an original PTO output. The crank still measured within spec on the mains and 0.001" under on the rod journals. After the rebuild I calculated the fuel mileage and calculated 15.

I've heard you can bump the compression in the 250s by using 307 pistons and in the 292s by using propane pistons.

I really like the straight 6's. Plus their easy to work on. I often sit in the engine bay on the the fender wells with my feet on the frame.