I have a 283 in my Task Force, I am using original cast iron Corvette headers. They fit fine - no clearance issues, I decided against tube headers because a number of people said they tend to warp and leak after a while. I don't know if that is true, but these headers are also useful because they have the mounting for the alternator/generator bracket. They show up on eBay on a fairly regular basis if you have an interest in them.
