They won't fit. And since you have to get new ones, I'd recommend Hedman Tork Step headers. I put a set on my 84 D350 with a 360. They were listed for a 4WD, but worked great on my 2 WD truck. Other than my TTI's on my Challenger, they were the nicest fitting headers I've ever had. Never leaked in the 4 years I used them. Good luck