It is hard now, and equally hard back in the day, to appreciate just how big the B-36 was. The only way was to park it beside something else that was BIG and note just how much BIGGER the B-36 was.

The photo above compares a B-36 to a B-29 from WWII. The KC-97 was basically the same airframe as the B-29, just a fattened cargo version. The wings, empenage, wings, lower section of the fuselage and the four Pratt & Whitney R-4360 engines were the same. The KC-97 used the same brakes as the B-36 to help out in stopping distance because of the heavier weight the KC took off at.
The B-36 had six R-4360s capable of churning out 3800hp each, combined with two pair of J47 jet engines for a boost on takeoff.
The P&W R-4360 was the largest reciprocating radial engine ever made. Each engine had 28 cylinders and 56 sparkplugs. It was typical that an engine would burn through 50-100 gallons of oil in a ten hour flight.
But those engines, whether on the B-29, KC-97 or B-36 had a characteristic drone that was recognizable immediately to anyone in the vicinity who had ever been around them. That was the sound that the crowd missed when the final flyby at Ft Worth was cancelled.
(I was at home at College Station in about 1985 and heard that sound. The wife and I heard it at the same time and ran out the door in hopes of seeing one of the old birds. Turns out it was a "Pregnant Guppy", a C-97 modified by NASA with a hugely enlarged fuselage to ferry rocket components to Cape Canaveral ... it had the same R-4360s. One never forgets something like that.)