what size that hood exit? 3, or 4"
for my ear / experience low velocity gas (i.e. 4" exhaust) exits on 6 and 4 cylinders all sound like sh8t at low rpm. personal taste obviously but holds true for me across a variety of platforms and firing orders.
back pressures not an issue for that length so maybe try and reduce that diameter, since you did all that work already. might only make a difference for full exhaust length but worth a shot.
for my ear / experience low velocity gas (i.e. 4" exhaust) exits on 6 and 4 cylinders all sound like sh8t at low rpm. personal taste obviously but holds true for me across a variety of platforms and firing orders.
back pressures not an issue for that length so maybe try and reduce that diameter, since you did all that work already. might only make a difference for full exhaust length but worth a shot.