I dyno tested a Torker 2, Mopar M1 4150 single plane and a Edelbrock Performer RPM on the same engine the same day, about 20 minutes each to change them, with no other changes. The torker 2 was the worst by about 20 HP and 25 Ft Lbs torque, the M1 and RPM where close to the same on the average readings from 3000 to 6500 RPM, the RPM was beter below 5000 RPM and the M1 was better above 5000 RPM If race only the M1 would be my choice, if street and strip I would use (do and have) the RPM intake I have not used the other intakes you ask about, sorry EDIT, I sure wish they had spell check on here maybe I should proof read better