I agree probably around 550HP. It's an all steel car with full interior, the motor is a very mild 10:1 compression 500" low deck with ported Eddy heads and small 557 purpleshaft cam along with small 1.75" B-body headers with a lot of dings. Lots of torque.

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