the heads i want to use have no smog holes.can i plug holes in metal tube at rear of heads and leave rest of smog system in car.will this set a check engine light?Fordgazm said:you can get rid of it all . The heads you need to plug off the hole in the back of the heads . pm ghostdog50 he knows what size bolt to use . You also have to plug off the hole in the H pipe where the tube goes in . Then you can get rid of the smog pump and all that junk .