Kinda late on the post but I got 18mpg doing 70mph but that was when I had 4.10's. Mine is EFI with the Ford AOD trans, for a wheeler I wouldn't use a carb. I think with the 5.29's I'll do just as good because the engine isn't working as hard to keep up the speed. I'll let you know what I end up with if your still interested <img src="/forums/images/graemlins/kewl.gif" alt="" />