[Jay S]

You can compare the factory rods in this photo I took some years ago, left is an early rubber rod, middle is a late cast, far right is a mid 70s SD rod. There isn’t much strength where the I beam attached to the rod throw or the cap on the early rods, both are pretty thin. The cast rods are stronger, beefier in the places the need strength, and also weigh more. Either would work fine for a stockish street engine on a budget. I don’t think ARP bolts would add any strength to the early forged rod at all.

I built dirt track Pontiac’s with both the early forged, and the later cast rods in 455s. Usually held the RPM’s to 5000 maybe 5500 on most nights. We ran the early rods in a 455 for a full season. Midway thru the next season we had a night 3 rods decided they didn’t want to be attached the crank anymore. Amazingly it still drove onto the trailer (on 5 cylinders) and didn’t hurt the block. Maybe that says how soft the metal in those rods is though, and it failed rather spectacularly.

I have a friend with cast rods in a 455 hitting it with a 100 HP shot of NOS.

All Jim Hand ever ran in his 11 second 455 power wagon was stock cast rods. He even broke one crank, but to my knowledge never had an issue with the stock rods.