Do some research. There are a few old threads about this. I think I read it on both, but found more info on FJ if I remember correctly.
And I have one sitting in my garage for the day that I finally open the valve cover.
04 ZX3 Mostly Stock [3/13 ROTM]["Best Non-SVT" FITF '12][7/14 ROTM][2014 ROTY]
12 SE Hatch Sport & Winter Package, ST Front End
94 F150 XLT 5.0 HO, OBDII Swap
89 Bronco II XLT Crawler