Connecting rod nuts

circlepilot said

It was never my intention to use "hardware store nuts." I was trying to find some specifications on OEM nuts without much luck. In my application, I believe it is not necessary change my rod bolts, (however, I may just cave and spend the money for the new bolts and resizing the rods, est. $150.00) but would like to just change the nuts. The OEM nuts are not "flange nuts, which seems to be all that ARP has. Fastenal has a grade 8 3/8 24, yellow zinc plated nut, (made in China) which seems to be where all this stuff is coming from.
Norm

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Was just checking.

The nuts aren't the critical part. The bolts stretch, which can cause failure if reused. The nuts, unless damaged, should be perfectly fine for reuse.

My rule of thumb has ways been that if I can't measure a reduction of the major diameter (or in the full diameter Shank, but that part is often unaffected) of the bolts, then they can be reused. If there is a definite reduction in the thread major diameter (.005 or more) then just replace them. Calipers are OK, but I much prefer a mic for this check.

This is also subject to the intention of the engine (performance builds should always get new hardware) and of course on how much it would suck if the reused hardware fails. To me, $150 is cheap insurance. Not everyone is in the same boat.