What drove the pump? PTO on the brownie, or was it solely gravity dump?
I can see why they would have repowered it. A fleet I cared for had a '51 450 dump truck with a 270 and it was painfully slow. Had a 5 speed and 2 speed axle. 10.00 x 20 rubber.
I drove tanker for years, often delivering 10K gal. truck-and-trailer loads to bulk plants that still used similar trucks for local delivery, some of them Texaco. Hoopies we called them. Lots of farm tanks are 10 feet high for gravity feed and so had to be pumped into.The PTOs on our big rigs ran off the brownie so you could pump in 1st, 2nd or third gear on the main box, depending on what product you were pumping. Often there was nobody around when I arrived so I had to figure out their plumbing and find the right key from a 6-inch ring hanging in the cab. Sometimes our pump and sometimes theirs. And some of these plants dated from the 1920s. There's only one of those left so far as I remember. Being short on seniority, I usually drew a truck powered by a 270 hp Cummins, which was just a 220 with a smoke kit (turbo). It was about as fast at the 270 cu in GMC but with a lot further to go. Fifteen-hour days back then. Occasionally, I would be weekend-relief on one of the Union-oil tenders and these were new Petes with 350 Cummins and 13-speed Roadrangers. It was almost like a paid vacation.... cut more than an hour off the trip over the hump.
The local ex-highschool community center has an AD 450 tanker sitting out back that they haul waste motor oil for the heating plant. It has a 2-speed axle that's stuck in low range so it's pretty slow but they don't go far with it. It's faded yellow so I think it may have been a Shell Oil truck. Same body as yours, including the pintle hook. How would you like to wrestle full oil drums in and out of the back? I used to drop them on end onto a truck tire but it still took 2 guys for safety. About 500 lbs. each. Some places had an oil-drum hand truck but you still had to get them onto the ground. We loaded them with a fork lift with special barrel arms.
