More often than not, when the stock rods fail due to abuse, they seem to fail in the same location: mid-beam.
General consensus on this forum seems to be that a well prepped, inspected, resized and refurbished oem connecting rod with ARP bolts will handle 550-600HP. Polish the beam section and you may get more out of it. I am assuming about 6500 max. As will all stock componentry, the power handling capability of the rods is ballparked, and other factors such as piston speed/stroke, piston wieght, etc all play a part in how much power they will handle
Many have successfully run them to 7500rpm or pushed them to higher HP in the right combination of build. On the flipside, though, a forum member announced his "fluke" oem rod failer at just 4500 rpm. Point being, once this rod is fully refurbished, you will still have a twenty year old forging on your hands.
While I am truly
a fan of using as much of the oem componentry as possible, the rods give me pause when it comes to utilizing them in a build greater than the 500+HP range. But that's just me
, and others will feel comfortable and have success with them in more powerful engines. Personally for me though, at this 500+HP number I tend to consider a replacment rod...specifically the Eagle SIR I-beam rod. For the amount to time, money and labor it takes to prep an oem rod, you can just go out and buy a brand new set of Eagle SIR's that altready have 7/16" ARP bolts in them (oem bolts are 3/8"), are brand new and "rated" to 700HP. I see them as insurance/a wise investment toward a shortblock that I have a lot of time and money into. Also, I like to overbuild my shortblocks so that I feel really comfortable that they can take pretty much as much abuse as one could reasonably throw at them.
And with that, 500HP and below should really be no problem at all, most people push well prepped ones to as much as 600Hp. More may be possible if you hand select the rods and prep them well, but I ain't about to recommend this.