Double adaptor hey crumb

I plugged that hole on my a14 head by drilling and tapping it. I created my own grub screw and loctited it in. Followed up with some builders filler and matching silver paint.

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I don't know if this will help, but I fitted a GM temp sender for my ecu by running an m8 die over it and screwing it straight into the head where there was a spare bolt hole. Does the trick and cost bugger all.

Ah! You're referring to the sensor that tells the ECU when the engine is warm, thus leaning off the air/fuel ratio, or ceasing the cold start (aka "auto choke") mode.
If the sensor has 2 terminals like a non-EFI sender unit, the plug would still be the easiest to change to suit a sensor that fits the manifold, as it doesn't matter which way the wires go. Try taking the sensor unit to your local Auto One or equivalent parts store (not Super[market]cheap as they generally don't know #OOPS# from clay) and tell them what you want. If my local is anything to go by, they'll pull the Trident catologue and try to find you one that is the same length to suit your manifold thread diameter & pitch. There might even be one with the plug you need too.
If you do find one, buy 2. If you plug the spare into the harness but leave it hanging free, it will read the ambient engine bay temp. This will make the ECU think that the engine is still cold and may show up as a fault, but it will make your engine run fatter!

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Come to think of it, isn't the L's temp sender unit located in the head, like the A's? I'm more A series than L, so forgive me if I'm wrong on that...

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What motor you running? A Series & L Series share the same sender unit if that's any help. Also, the easiest thing to replace would be the plug itself.

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