The difference in Net and Gross is the accessories on and functioning and the exhaust system. The drivetrain loss is not taken into account. So a Gross rated 318, in 1970, had 230 gross flywheel hp. That was the engine, driving the water pump and fuel pump, through manifolds. A 5.2L Magnum 318, was also rated at 230 flywheel hp. But it was rated with the water pump, power steering pump, and AC compressor w/clutch engaged, thru factory manifolds and exh including the cat. At least that's how I understand it.