Friends, do You know a replacement for the original part number NAB3580DA?
It is a spark plug for XJS MY 1988 5.3 US version, emission A.
Thank you very much in advance.

 

I use NHK BR7 EFS. But there are lost of others.These are the specifications:

Specifications for NGK BR7EFS

• Thread diameter: 14mm
• Thread reach: 17.5mm
• Seat type: tapered
• Hex size: 16mm
• Tip configuration: non projected
• Construction: Standard construction
• Terminal type: Solid

Other for instance:
https://www.ebay.co.uk/itm/301517682...3ABFBMrpD_oN1m

Just make sure you buy plugs for the HE V12; not the pre-HE!

 

I think there was a revision that the one recommended were BPR7, but the NGK are good plugs. Heat range 7 is what is best.

 

NGK BPR6EF or BPR6EFS down here.

Gapped to 0.025" please.

Never Seize or similar in the threads ALWAYS.

 

Thanks everyone for the responses. I use BR7EFS, but as Greg writes, I'm looking for the difference between nonHE and HE spark plugs (which is NAB3580DA, according to Jaguar specifications, a HE spark plug). I found DENSO T20EPR-U and NGK BR7EFS (3177).
The question is whether they are for HE engines.

 

See here
https://www.denso-am.eu/catalog/part/T20EPR-U