Wondering what would be the preferred header and collector sizes for a 383 stroker with a hydraulic roller, aluminum heads, and a single four barrell operating in the 2500-7000 RPM range???? I've looked at everything from 1 5/8" tubes with a 3" collector to 1 7/8" with a 4" collector....and just got confused on what might be the best size to boost the power (especially the torque) on an SBC.....