Mine were Dynatech's, only got them cause I liked the headers, post by a guy called "pic" who works for a cat fabrication out fit said they looked very cheap as far as internals go, but alot of different brands failing under forced fed applications going by this forum, sounds like a problem with quality control as alot a brands all come from same factory as far as the gutts go. I wont be using any in future, just cost me 10G for parts! Mind you some upgrades in there as well. Just not looking forward to the labour side of things, but don't trust any one else working on my car here but me.