2004 RC , never removed the valve covers, so basically stock internals. I have full length headers, custom equal length true dual catless exhaust with an x-pipe, ported intake by Form & Funtion Performance, BBK throttle body, 170 therm., underdrive pulley, Volant Ram Air, aluminum flywheel, 4.56 gears, Tune by Chris at DC Performance, JTS Venom coils and wires, and SCT race tune. DynaPac numbers at DC Performance....
SCT Race tune 541 rwhp, 572 ft lbs. (50/50 91 octane/ 100 octane)
SCT stock tune 538 rwhp, 568 ft lbs.
The DynaPac is where they remove the rear tires and mount the dyno machines right on your axles. So the numbers are a little higher than regular dyno's. But the truck runs 11.90's and the dyno websites where you put in ET and MPH plus the weight of the vehicle usually say from 534 to 565 HP.