For my two cents, If you are looking at long tubes on a coyote, you will need to drop the K-member, It's not terrible but it is more work than it looks. And for some of these headers, you are looking at a potential for 10 rhp increase which is the same as shorties. I know my kooks are real close to the K member on drivers side and I worried about false knock but everything is good. Some of these bargain basement headers require denting of tubes to clear steering shaft. And you also need to purchase based on your other mods. Don't buy 1&7/8 tubes for an NA application, it's not going to help you in the long run as there are trade offs to be made. There is a reason why Kooks/American Racing/ultimate are so expensive, they are properly tuned and don't have fitments issues. Every mod I've done has had unintended issues even buying name brand components. My green cats launch catalyst efficiency codes from time to time.
It's expensive to mod coyote, you want to go cheap, swap an LS in or be happy with what you got.