[markjohnson]

I'll tell' ya....I've got one those #569 "pancake" intake manifolds that's orignal to my LS-6 and the funny thing is, if you turn it upside down, all the runners resemble a #163. I bought a magazine from the early '70's last weekend with an NHRA Stock Eliminator Chevelle that uses a #569. In the article, they stated they had compared it greatly to the Hi-rise, that the runners measure out exactly same, and performance was equal in their limited camshaft applications. For what it's worth.