NGK TR5-1IX spark plugs?

Hello to all ,

Yes I remember that we used to INDEX our spark plugs all the time when we were racing the "showroom stock" series. Every bit helps at this level. As to my NGK TR5 plugs I put them in this morning and my baby purs like a kitten. The rough idling is gone. I must say though I do not think the Autolite plugs had any problems, they were just worn out. They have about 400 hrs or so on them so a new set of plugs was welcomed. I did check the engine temperature at full throttle and it was excatly the same as with the Autolites , 160 degress on the nose.

Thanks to all, Enjoy the boating season!