Nice picture ot the Brasil ENGESA CCKW 353 GMC conversion. This photo was publisched in THE OBSERVER'S MILITARY VEHICLE DIRECTORY from 45. The rear axle boogy is the beefed up spring with a walking beam system added, also bigger tires, In the US-section of the directory there are several 8x8 pototypes listed with payload 2 1/2 to 6 ton.
The origin of the DRAKE photo I do not know, however, there is an other one in DUKW 2 1/2 ton 6x6 Amphibian of ISO publications, London, 1972.
In the THE OBSERVER'S FIGTHING VEHICLE DIRECTORY WWII you will find some US 8x8 protypes which never saw real service.
The Swiss built a nice 8x8 Saurer tractor to hawl the heavy artillery before WWII already (7.5 ton GVW, 100HP Diesel). As far as I know, the last ones were sold about 10 years ago. But they are no good for the states, the max speed is about 60 kph or 35 mph! Trans is not syncronised, no power steering, only air brakes (single line European type swiss version), right hand drive, no power assised clutch; it's realy hard to drive, I tried it.
Wolf