Spark Plug Choice KZ1000

I am buying new spark plugs for my Kz1000 and found that there are three choices (All NGK) B8ES, B9ES, and B7ES. Which should I buy? I saw another thread on this but I didnt really explain the differences.
I have a '80 LTD 1075cc 4:1 Kerker Stock Pumpers with KN.

Your bike is a larger than stock bore so that may make a difference, but the 1981 Kawasaki Service Manual calls for the B8ES plugs. The B9ES plug is one heat range colder; the B7ES is one heat range hotter. Colder plugs are normally used when the bike is ridden very hard. Hotter plugs normally are used if the bike is used very gently. Ed

the manual says B8ES

the different number stands for the heat range of the plug.

I use B8ES in my 80 LTD 1000 with 1075 kit & RS 34s & it runs Great
Pete

Stick 9's in it.

Another choice(if you can find them) is the Denso W24ESU's, same spark gap.

I always run B8ES or B8EV in street motors, even if they're pumped up. Never any problems. V's cost more but IMO they're worth it.

You can even run Champions if you like but do not use anything but the direct cross over plug because Champion heat ranges and NGK are very different. One range in a Champ is equal to about 3 in NGK.

+1 on the Denso Plugs. I use their racing plug, W24ES-ZU.
I've always like the Denso and NGK plugs.
There are a lot of different electrode types out there. That is one of the big differences in plugs. Then of course there are resistor plugs, which you Do Not Want. So if someone tries to sell you a set with an "R" in the part #, say BR8ES, pass and get the non resistor B8ES.