A while back I bought a set of ARP Ford FE rod bolts to fit to a set of S AEG521 conrods. I knew that they need some minor polishing of a knurled ring under the bolt head but it seems there is actually a bit more involved to get them to fit.
I may need to increase the chamfer in the rods to clear the radius under the bolt head, which is fine. However the actual bolt heads seem to need some reshaping to fit into the spot faced relief in the rod. Either that or the rod would need relieving. Has anyone else had to do this or have I just got a set of rods that have narrow spot faces?
I'm inclined to relieve the rods so that in future replacing the bolts would be pretty straightforward. Any thoughts or advice out there?!

There’s a few posts on here describing what’s needed if you search. DocMini was one of the contributors.

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ex-NSW Police 1970 MK II Cooper S
VMCI #43

I have a set of new AEG519 bolts if that helps!

Thanks for the responses so far. I have already read through all the old posts looking for tips but there is nothing specific, just one reference by DocMini to linishing the bolt heads. I might try reaching out to Doc directly to see if he can elaborate on what he has done in the past.

Have used ARP Ford rod bolts on both of my Mk2 S motors with AEG521 rods. The bolts do not fit through the holes in the rods. I had to linish the knurled part of each bolt to allow the bolts to fit, using a lathe and emery cloth roll. No other modification was needed.

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Clive G
1969 Mk II Cooper S
1970 MK II Cooper S
1963 Triumph Spitfire
1982 RX-7 Series 2

Hi Clive that's interesting. I knew about the mod to the knurling and have a small lathe so no problem with that aspect. I think I may need to turn a few thou off the actual bolt heads so they will fit into the spot faced surfaces of my rods.

Okay, so after some quick measurements today it looks like I will need to turn about 55-65 thou off the OD of the FE bolt heads to fit my rods. Comparing to the original design this still allows plenty of clamping surface under the head. In fact probably as much or more than the OG bolts. Will post results when I finally get some time on my lathe...

The last 3 sets of arp I bought fitted straight in.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Same Kev. Mine just fit in nicely without any machining.

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The bitterness of poor quality (or Crappy Workmanship) remains LONG AFTER the Sweet Taste of Low Price is forgotten.

Thanks again for the feedback all. Looks like I just have some brummy rods then. Bugger, but should be easy enough to sort out hopefully.