I have a new Blueprint Engines 408 and currently am using the original 340 manifolds. I bought TTI 1 5/8" shorties for the project but am rethinking my decision to install them. Anyone have experience with performance improvements between the two? The car will be used on the street only and max RPM 5500. Car has 3.23 gears with 28" tires and a PTI 3000 stall converter. Thanks guys.