Homegrown: “666” hot rod packs triple the Stovebolt,

[Bob Riebe]

https://www.hagerty.com/media/car-profiles/homegrown-666-hot-rod-packs-triple-the-stovebolt-triple-the-fun/

Noble gave his engines an 0.030-inch overbore to increase displacement from 235.5 to 239.5 cubic inches per block, achieving an awesome 718.4 cubic inch total. Fitted with dual-carburetor intake manifolds, tubular headers, and mild Isky cams, this 18-cylinder team delivers 550 horsepower by Noble’s estimate. Not to mention enough torque to rotate the Earth on its axis.

[Lloyd Smale]

had a buddy in the service with a hopped flathead ford pickup. it wasnt all that fast but it was the hands down best sounding motor i ever heard when he got on it. That thing has to sound absolutely insane

[ironglow]

  One thing that contributed to the rich sound of the old flatheads, is that the distracting valve train clatter was deadened, because the valve train was encased by cast iron...not tin-thin valve covers..

[Lloyd Smale]

 they sure sounded "mechanical" much more so then an ohv motor