ol' school power wroteA collector won't work. The end of the tubular is in the same position as a factory cast manifold. It should be a 2-1/2" and shaped to connect directly to a factory down pipe.
Ahhhh...now I see. Is this smaller diameter outlet of the edelbrock headers compared to full length headers, the reason shortie headers can sacrifice some power? Or is the 2 1/2 Vs. 3" collector negligable towards power production? I would tend to think that once you get to 2 1/2" that 3" isnt really going to show much gain ,if any, in most mild street strip setups. On the other hand tube length and collector length was at least that's what I have always thought was more influential?? Thoughts....would a 2 1/2" collector Vs 3 actually be BETTER for exasut velocity?? Hmmmm :-|