WidgetBucks - Trend Watch - WidgetBucks.com
Heat range for NGK plugs 2 HOT - 11 Cold
JIS length - 53.5 mm from seat to plug tip. STD GT-R plugs are JIS length.
ISO length - 50.5 mm from seat to plug tip
Racing NGK plugs. Recommended by Nismo
R7436-10 part number 4900 $ 38.81 each JIS - I like
The Denso plugs are not to be used. The ceramic around the electrode breaks off and drops into the combustion chamber under hard running. I have ruined several motors because of the Denso spark plug. I wouldn't use them in a Lawnmower.