Just wondering. I'm watching The History Channel about 60's and 70's musclecars. They talk about 405 hp on a 63 factory racer Pontiac Catalina 421 cu in. That's the old world hp figures. What would that equal in todays hp calculations? I think about the late 70's (?) the mfrs changed the way they figure hp? So our "500" hp SRT's would be 375 hp years ago or 600 hp? Any of you gearheads understand this? That's a compliment by the way. Thanks alot!