Needed one 73-74 Super Duty connecting rod nut.
 

I have a set of the late Pontiac rods that is missing one of the rod bolt nuts. This is what happens when you hoard things away for 25 years. 🙂

Apparently Pontiac used an uncommon 7/16" thread pitch and finding a replacement nut has been fruitless.

Hopefully someone here has a spare they are willing to part with so my 389 project can move forward.

Thanks in advance.

I have a set nos

I have zero knowledge of the BBC 7/16" rod bolts pitch, but chevy used 7/16" bolts in some of the factory HP rods. There have to be more of those out there than SD rods and bolts lying around. It might be worth a try rather than breaking up a set of NOS rod bolts for a Pontiac.

:2cents:

My machinist (Archie @ Sommers Automotive Machine) looked through all of his stuff and came up empty handed. He said he has run into this problem with some odd Ford stuff in the past.

Thanks, but breaking up a NOS set for a single nut wouldn't be right. ARP's web site shows they sell pairs. That may be my path forward if I can't locate a factory one.

I have a full set of SD-455 factory rod bolts and nuts. I do not know if they are NOS or not. They were installed in a fresh rebuild SD-455 in 1979. The engine was never started. But I do not know if they were the OE bolts or NOS when they were installed. That is why I did not use them. Important note: If your holding out for one rod nut, please be aware that they are not 7/16" SAE fine. They are a special thread pitch, not fine or coarse. If you buy ARP replacement bolts, they are NOT the special pitch, they are regular SAE 7/16-20. So in summary, you need the specific nut for an SD-455 rod bolt to have the correct assembly. If you have a need and desire to use the OE SD-bolts, PM me and I will sell you the set at a very reasonable price. Finding a single correct nut will be pretty difficult due to what I mentioned above.

I found the thread pitch. Those nuts are 7/16-24 UNS (Unified Special Thread)

Not if the right guy see this ;)

Those nuts are a issue. Way back in the day I bought a "new" set of SD 455 rods from a guy in New Hampshire. But when they arrived at Whitmores 's shop the rods were in fact new but someone took the new rod nuts and replaced them with used nuts.
They did work fine but I used red Locktight on the treads, just in case.
Sold them for 400$ locally, kind of wish I still had them.

i'm pretty sure i have an extra set of those sd455 rod nuts ....i will look for them tonight

Thank you everyone for your insights and offers! Good guy Paul K had one and has shipped it to me. Hopefully I can deliver it to Archie's on Monday and continue moving forward with the problem child 389.

Thank you very much Paul!

I believe in miracles!!!

My thought would have been someone that knows Nunzi...

It was a Thanksgiving miracle! The nut arrived Friday morning.
Thanks again Paul! I hope your Thanksgiving was as good as mine.

I have an old SD rod lying around that is no good, still has bolts on it, I'd give it to you for the cost of shipping.

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