They will fit and work fine, exhaust face on the bpe heads are flat, so should probably seal better than on the old ones. I actually use a modified LS 1 7/8" swap header with those casting and the outside 3" bolt pattern vs the oem ford one, but I ported them a long time ago and was complete budget set up where I built the heads out for under a grand, many switched to a more D shaped exhaust port years ago copying afr's stuff. That casting is branded by many even afr as the enforcer and most don't have any issues making decent power with it. Even the cheapy 100-150 China stainless shorties everyone sells now will work fine on those, some of the shorties just have way more of a square/ rectangle crimp at the port than others do and yours seem to haves a real heavy crimp to them from the pic, how old are they, bbk has changed their shorty design a few times in the last 20 odd years, last one resembles the P headers with the swooped out number 5 primary. Either way I wouldn't worry about to much as long as it seals.