I love history. Especially automotive history. It would appear (historically anyway) that about the time that that engine was built aftermarket support for Chrysler connecting rods was pretty sorry. From my research about the only steel rods at that time were offered by DC and Carrillo. And the Carrillo’s were really expensive. One option was to use a 6 inch Chevrolet rod, and decking the block about .125 to make it all go together. As I posted earlier, the pistons are out of the deck about what I thought. When I looked at the piston in that engine I saw a pretty small compression height. That means that either the stroke is pretty long (it’s not long by today’s standard) or the rod is really long (6 inches is not a long rod) or the block has been decked to make it all work. If I had that engine, I would change the rods to steel, get the compression down to a pump gas number and change the cam. Then I would go out and beat the brakes off it like I stole it.