Didn't most of them bolt to the stock manifold or of course FENTON orignal street headers have a heat riser cast on them. I don't think anybody is repoping them. Then of course they went to the heat plate but it bolts to the same pattern on the intake but they don't put exaust into intake manifold, it just heats the bottom of intake as a riser would. Anything tapped into intake aia would think is for vacuum. WDIK 1 OL REDNECK
