I have a 1987 E350 motorhome with a 460 engine. I would like to get rid of the stock exhaust manifolds since they leak and may be cracked. My biggest problem is that no one seems to make headers for that set up with air injection. I would like to get rid of the smog pump all together but I live where I have to be tested every two years. I was thinking of deleting the air pump, adding headers and then installing a high flow cat. Does anyone have any experience with the E350 and what to do about the stock exhause manifolds? Does it sound like this set up will work and take care of the emission part of it?