Black Betty (Adrian) has tooooo much time on his hands..... Lol!
http://www.fourwheeler.com/how-to/engine/154-0911-jeep-4-liter-engine-myth-busting-true-lies/
Correction, black betty does not have a heated garage, therefore time which would normally be spent wrenching is spent researching what he will be wrenching on when he has a garage. Preferably with heat.
I came across this article while looking into headers. Although it is an opinion, there is some value into what they are saying, and ive never been a fan of seat of your pants reviews.