L&L is about the only place that I've found who supplies them for that application. I'd suggest going with 1967-79 Full Size Truck/bronco - 429 & 460 Swap Kits - Headers
When I bought mine 3 years ago, they were cheaper through them than directly from L&L and they are the same header. If you do go with Broncograveyard, call them first because it's possible they won't have any in stock since they get theirs from L&L. They are an expensive header but well built and about the only header I could fine. I run chassis exit and they fit just fine without any modification. The fenderwell exits only require a little triming of the inner fender.