3rdCoastPowerSports

iTrader: (5)

I know I have removed both the tapered and the washer'd spark plugs from LS aluminum heads. Can you use either tapered fit or a washer fit plug? does it matter if the head is aftermarket or stock? why do they make two different fitments of spark plugs? is one better than the other? I always use NGK TR55 but im almost positive I have seen the NGK TR55 with both the taper and the gasket. maybe im imagining things.

Jontall

It's always a tapered seat... If you removed plugs with a washer, they were the wrong ones in there.