All of them have little "cliffs" and "ravines" that fit together . Some need to be 'worked into place" a little bit . Within reason , I think those can actually be better at keeping their contact patch aligned at high RPM , under detonation , etc .

A rod vice , or even a set of soft jaw's for a standard vise make quick work of torqueing and disassembly during mock up .
And if anyone really want to add to the "junk parts pile" invest in a small dial bore gauge ..

I'd give a random cap to one of my friends in the aero forensic lab for analysis . But when we looked at the scoped images and read the report , none of us would ever want to use one of those rods ever again ...