I love the 590! I installed it at 104 in a 3050# DartSport with an 11.2:1 451.
I used Harland 1.6 rockers on the Eddy heads, Isky 8005a springs with steel retainers. Ran 9.90's at 136 MPH all motor. New owner has gone 9.77 in the car.

I never tried advancing the cam more, I wouldn't want to lose MPH and it had PLENTY of torque at 104.

1970 Challenger, all aluminum 528 Hemi, HDK suspension, Tremec 5 speed manual