I like the stock rods as they have oil squirt holes to oil the cylinder bores...
The aftermarket companies claim that you don't need them and don't have them... However, I'm not willing to be their guinea pig to find out... I would rather throw more oil on the cylinders and let the oil rings do their job to wipe off any excess... It's better to have too much oil, than not enough...
The issue with running old stock connecting rods is that every time that you torque the nuts, you put some permanent stretch in the bolts... Every new clamp cycle adds to the stretch... Eventually if you keep going, you will get to where the bolts will neck down and break...
I worked in an engine factory. Fastener engineering would allow a MAXIMUM OF 5 CLAMP CYCLES on the bolts before they should replace them... They also required that we should leave one clamp cycle for service and one for rebuild, so we were only allowed to tighten the connecting rods 3 times under our roof before scrapping the rod bolts... This meant that one cycle was used to machine the rod and cap on the rod machine line, then we separated them when we pinned the pistons to the rod and got ready to shoot them (install) in the engine. <that is two clamp loads right there> So we were allowed to only re-use a piston/rod assembly only once before scrapping...
When you replace the rod bolts, the knurl on them is what locates them in the rod and the cap to the rod... Changing them may offset the alignment of the original bores in the cap and rod, so it's best to have the large end of the rod re-conditioned when you replace the rods... I've seen a slight mis-match (.0005" - .001") between the cap and rod make the crank tight or even lock it up... I've seen a small piece of dirt or lint from a cotton glove on the back of the bearing make the crank tight... The more free the rod is, the less friction it takes up to spin the crank, which is more HP you can get out of the engine...
When they re-machine the rods, they mill a little of the face of the cap and rod, then re-size the bore back to it's original spec. size. That way you still have the proper bearing crush to hold the bearings in place and not spin one...
It's true that you can buy an aftermarket rod cheaper than you can get the old ones reconditioned, but I feel it's worth it to have the oil squirt hole... I like durability in my engines...
To build an engine right, you need to check the bearing clearances. Either by torquing the cap on the rod with the bearing installed and measuring the rod bearing and mating main journal with micrometers, and then tighten them in the engine... Or use plastic gauge - both ways require two clamp cycles ---> so I would say replace the rod bolts and have the crank end of the rod re-machined...
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