Thanks for the input! [thumb] I'm glad you've enjoyed reading about the build. I'm still willing to bet that any aftermarket shorty header will outperform the stock manifold of the same design. Overall, using a shorty header seems much easier than making our own header or adapting a 1.8L Miata header.Awesome build. Im considering a Zetec or Duratec in my MGB. Havent decided what build to go with yet. I'm getting a lot of great info from this. Keep it up and good luck.
Not sure the collector of that exhaust will "flow better." That abrupt change in the collector plate from 4 to 1 creates a significant pressure drop.