I sure hope you get some results from the R&D. From what I can determine, the rod cap is on to one side to make it easier? to remove the piston and rod while the crank is till in the block.
Somewhat a field rebuild/repair expedient idea. The rod bolts are not all that great in those, and if one loosens up, there is your rod through the block...
As for keeping that engine together, to make more than it does, one Item is obvious: the balance of the heavy reciprocation assembly is very important to the rpm ability of any engine, especially a heavy one with a long stroke. I do not know if the factory even attempted to balance them when new, due to low rpm expectancy of use, and the technology available to do it accurately at that time for truck engines. Even if the original design attempted a balance of sorts, as replacement parts were added over the years to an engine on government spec., at that time, some parts may be a little off, due to manufacturing differences, methods or day of the week. A mix of mismatched parts in this type of an engine will seriously affect balance, and will try to rip the engine apart from the inside, as the rpm climbs. Based on what I have seen, some harmonic balances on LTD 465 are not the best type for longevity, and can loose the bind between the outer ring and hub due to deterioration of rubber, chemicals and just age loosening it all up, until the balancer is no longer in balance, which will also greatly affect the engines ability to hold together under load and as rpm increase.
To my knowledge,?? I have not seen an aftermarket or a performance type balancer that would fit the LTD 465, but I did found one NOS, loose on ebay a while back.
Hopefullly you can find a way to resolve these irritating issues, that may increase the Deuce's power and durability.
Good luck to you.
ALFA2