My speed daddy's have been gold, no leaks & I had the entire lower portion welded up. I didn't even have to bang out the firewall for the O2. I could argue that while the setups for ZZP & WBS are very impressive, they are worth 25-40% of most GP's right now. I think a set of new ZZP's is equivalent to 30-35% of the cost of a turbo kit fully installed??