Spark plugs after cat bypass

[foot2firewall]

I've installed cat bypass pipes on my S3C - what is the advice on spark plugs; should I use the ones specifically for a non cat engine now? Is there any recommendation on part number and brand to chose?

[foot2firewall]

Thanks all for the feedback, it took a lot of plus gas and a spark plug wrench upgrade to get the first plug out! The head is marked F and the seat for the spark plug is flat, but the plug I removed is tapered, I guess someone overtightened it to compensate for being the wrong type. It's also not the correct temperature rating (5 not 6.) All being replaced with NGKPPR6ES tomorrow.