"I see where you are trying to go with this: So if it "had a standard bore" means it was never bored, and if that means it was never rebuilt and they don't last much past 50K and it is the original motor and it lasted til 2011 (meaning the original motor was the one immediately preceding the 56 in 2011).....maybe, I say maybe, the truck has 39K. Why was it replaced? Was the 216 running in 2011?
It may have, by circumstantial evidence, have 39,000 original miles if enough other condition items are present. Now let's forget it"


Yes the previous owner drove the original 216 splasher up from Bend Oregon to Vancouver Wash to Chev of the forties. He had 26" tires on it and it began to make a noise in the bottom end about 1/2 way back. He limped her home right around the end of 2010 I think. The 235 went in and it didn't get but a few more miles on it because the new clutch he put in with it slipped and made noise. After I bought her, I trailered it home and found the clutch disc was in backwards. I decided to do a body off at that point. Thanks for the comments guys.

1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration