Randy,
How were the rods held when the torque was applied to the pin clamp bolt on the small end of the rod? I have heard that the rod can be bent or twisted if the rod is just clamped in a vise. I slip a drift of the proper diameter through the pin and clamp the drift in a vise, and then apply the torque to the bolt. This puts a minimal load in the rod. I recall that I read about this method in a Hot Rod magazine back in the early fifties. The shop manual is a little vague on how to do it correctly. Were the rods checked for alignment as described in the shop manual?
However, if two of the pins were frozen after only ten seconds of running, it is not obvious that alignment was a problem. If the piston was warm when the pin was installed and assembled, and the engine was cold when the startup was attempted, the piston could have contracted enough to sieze the pin, especially if there was insuffient lubrication during assembly. A temperature drop of 50F will cause the pin hole diameter in the aluminum piston to decrease about 0.0006", while the diameter of the steel pin will only decrease by 0.0003". this would produce interference if the "warm" assembly clearence was less 0.0003". The shop manual calls for a "slip fit", which is looser than a palm fit.
Shop Manual I will be starting up a recently rebuilt 261 in a few weeks, so this is of extreme interest.
