Exhaust Pros/Cons for Slant 6

You want the 1-2-3 pipe to Y with the 4-5-6 pipe somewhere based on where you want the scavenging torque boost RPM to be. I put it around 50” back from the head which is around 2800 RPM. Doug Dutra put it back by the axle and he said it pulled hard off idle. After the Y 2-1/4” is plenty if you have no intention of winding the crap out of it.