Camshaft Selection Information

If it were me, I'd consider just buying some new Scat I beam rods. I'm not sure what the price is these days, but considering cost of resizing your rods plus buying new ARP fasteners, it may be cost effective. Also consider the rods you have are 50+ years old, not a part you want failing, nevermind talk of 6500+ rpm. Not trying to spend your dollar, just offering an opinion.
I appreciate opinions. I am thinking on this engine those pistons look like KB pistons from the top view with bore scope. With those style pistons I am wondering if someone had originally built up the engine with better upper end than the stock iron that is on it now but when they wanted to sell the car they pulled the new upper end off and put the stock iron back on it. I'm just guessing here. Will know more when I get the pan off.

Someone mentioned on another post that the factory rods had an extra oil hole to lube the cylinder and that aftermarket rods don't have that hole and could be some concern about the overseas material quality of aftermarket rods now days compared to the original Detroit USA material in the original rods?

I have never ran aftermarket rods, so I have not practical experience on them.