I'm confused... is this old school thinking? Isn't it far better to have all the tubes equal length to get the most out of your system? Or is this a race only item that has shown no benefit on the street? I am finally rebuilding my 70 4spd RR and it will have a 440 stroker instead of the NOM cast crank 383 that was in it. I was considering headers, but haven't decided if they are worth the trouble over HP manifolds. The RR will see street duty only.