[Rick Parker]

Just an outside chance but with the 69 block which has a marginally shorter deck height I think there is a specific piston pin height for that engine which is different from the later 351's, check into it. Outside of a twisted rod, be sure the rod cap is installed in the correct orientation and the rod fasteners are retaining their clamping force and have not been overstressed and most importantly that the finished bore of the rod is correct, it must create "Crush" on the bearing shell to keep it captive.