Most likely a shitty welding job. If you look at it, it started to crack right on the outside of the bead and just continued around. Also, the poor fitment of the crossover pipe could have had something to do with it. The crossover doesn't want to sit on the flange very straight, and it probably put a little extra pressure on the header.Originally posted by Zak8022
looks good man! i hope you get all those bugs worked out. any ideas on how the header got that f**ked up?