Frank Mcgurk conducted nine experiments on squeezing power out of a 261 as documented in Hot Rod Magazine’s May 1955 issue and he used the Corvette exhaust manifold for all but the first (bone stock) test and found no shortcomings I could find. Test number 9 with his triple manifold resulted in the following statement:
“No provision is made in this manifold for exhaust heat to aid in keeping the mixture charge in a gaseous state. As a consequence and, as one might well expect with a “cold” manifold, engine performance and fuel economy are not of the highest order at engine speeds usually encountered in city driving.”
Here’s the article:
http://www.selectric.org/55chevy/soup.html
