My son just called from his shop class and his shop teacher told him he needs exhaust manifolds for his K5 Blazer. It seems the ones he has are warped. He wants to install headers which is ok with me. He has a 4wd 83 K5 Blazer (noAC) to which he is installing a rebuilt 350 engine. I have to give him credit he's done most of the work himself. Any recommendations on headers? I just want to make sure they will fit. I found some on eBay, 1/4" flanges, 1 1/2" tubes and 3" collectors. The add says they will fit a 67-87 C5 & K5 Blazer/Jimmy. Any comments and/or suggestions are welcomed. Many thanks!