Check with Paul Kane on the forum, he's an expert on them, if I remember correctly I believe that the small end around the wrist pin is thicker on the newer rod over the older truck rod, and the passenger rod is the weakest with the machined rod bolt surface squared off.
The late F250 truck rods were the F6TE-BA rods. I think that there is also an F3TE rod, but my memory might be playing tricks on me (long weekend).
In layman's terms, we refer to the late F250 truck rods as the "Double-Dimple" rods because of their two forging spots formed in the beam area (all the other OEM 429/460 light use engines have single dimples in the beam area).
One way to identify double-dimple rods is by their F6TE-BA (and F3TE?) forging number. Another is that the balance pad on the top of the pin bore instead of the side of the pin bore like the typical passenger car rods and D6VE truck rods. These rods are F6TE connecting rod forgings and came in the very last of the 460's, and were sold as -A75 rods through Ford Racing. I think a bushed version (bushed to 0.990" pin) is what the 514's originally came with before going to an H-beam rod.
About 7 years ago, me and Charlie Evans laid these two types of rods side-by-side for a comparison. Here are the physical differences:
Above picture: The typical CJ rod is on the left while the late-model "double dimple" truck rod is on the right (see the two dimples just below the "8" written on the rod). The connecting rod mass is written on each respective rod. Note that the late model F250 rod is heavier by about 35 grams.
Above picture: Note the additional material around the pin end. These double-dimple rods have been bushed and floated, so don't forget to take the bronze material into account as additional thickness around the pin. Also notice how the I-beams come together beneath the pin boss on the Double-Dimple rods.
Above picture: Note the additional material around the big end, especially the rod cap.
Obviously, the additional material at both ends plays a big part in the increased mass of these connecting rods.
But are they stronger? Well, since the OEM rods seem to break mid-beam, I asked Charlie for pair of micrometers, he whipped 'em out and measured the mid-beam rod thickness, and we found these two different rod forgings to be within 0.010" thickness of each other at the mid beam. Since that's where most OEM Ford rods break, they may not necessarily be any "stronger" in that area than the usual passenger car/CJ rods....however:
They are not 30-year old "cycled-a-million-times" rods but are newer than the CJ rods. I think that stands for something.
They are meatier in the big end which minimizes distortion...less likely to pinch a bearing/grab a journal. I think that stands for something.
They are meatier in the pin end which makes them less likely to allow a piston pin to drift into a bore. I think that stands for something.
But still, we hear of more rods breaking than we do of them grabbing bearings due to big end distortion at speed.
Ford blew 'em out of their inventory a few years back....yet another part no longer available for these engines.
Not to hi-jack but Paul do you have any pictures of broken beams on stock rods? Haven't seen one yet around here but seen dozens of broken bolts. But there are not many people racing 460's around here. Would like to see if there is a specific area on the rods that extra attention should be paid.