I habe 2004 pontiac bonneville sle v6 what the best spark plugs for me

Hello group new here I have a ? I'm being charged 550 for replacement of coolent elbows on the back of the engine gal of coolent and belt is that price fare I have 2004 pontiac bonneville sle

Hello I'm new to the group been fellow the page for awhile I own 2004 Pontiac bonneville sle. Always looking to see how and update her or just get more information