TTI Shorty Headers

I'd expect some benefit from the shorties all across the RPM band vs manifolds, even the 340 ones. The Spitfires on my son's 340 '65 'Cuda gave better ground clearance than I would expect overall from a 4-1 setup, but that may or may not be important to the OP. We re-located the oil filter remotely to fix that problem.... which I like to do and consider a plus anyway.