Interesting, I had heat sensors fitted to my fore and aft core plugs, but they were stick on, and registered the max temp attained…I think I would be tempted to plug those in the back of the head, but dialogue with the rebuilder should enlighten you…
got the receipts emailed to me for this rebuild, which included new stepped sleeves bored 30thou over, 9:1 pistons, crank sludge plugs done, new everything, manual choke conversion, dynoed, little touches of class like copper washers everywhere backed by bellville washers etc etc…the ebay seller got a bit cranky when he found out, but I was the only bidder at $300, as his description was “XJ motor, was working when removed”
I saw Mike’s “Sacrificial Anode”, and thought, “ok, fair enough”, but I kept wondering what kind of madman would drill a hole through a core plug, either before, or after installation. So I googled about a bit.