1965 289 piston damage
 

Motor was rebuilt and assembled by a local machine shop. At 200 miles the motor started knocking and was towed back to the shop. The shop presented 4 pistons with damage to the pistons below the rings. The pistons were located at the 4 corners of the block. They rebuilt the motor again and within 200 miles the exact same thing happened. They blamed it on the distributor both times. This sounds absurd. Any ideas out there. Does anyone have a link to a picture of the location of the oil galleys on a 289. Thanks to everyone.

I was thinking that it might be a fault in the crank/rods or cylinder walls. Possibly the cylinders were not honed/bored before the first rebuild and the pistons slapped around in the bore too much. The second time around it was just worse. Or maybe the crankshaft or rod bearing toleraces were too great and the piston slapped around some more. I guess the solution would be to bore the cylinders and main bearings, and maybe try out a new piston/rod setup.

same thing hapen twice must be bor to much piston slap if it brakes below rings have them check bor see if it egg shaped