Dumper cab over maxium weight for the law is 60 tons. But the technical maxium weight is 75 tons The middle steer axle is not powerd, the other axles are al powerd. 60 tons is 120.000 lbs correct me when a'm wrong.
It's definetly not from 1976....The truck facing you to the left of the CR England Mack is a Ford CL900, a model that was introduced in 1978, Also the WCX Freightliner to the left of the Ford has the later style "bulkhead doors" which were not introduced until 1981 so that would put the date not before 1981.
BW900, I also see several International 9670's which weren't introduced until 1981, so you are definitely right about it being post 1978.
C series FORDS introduced in 1977 1977 April 14 - Three-member Office of the Chief Executive established: Henry Ford II continues as chairman and chief executive officer; Lee Iacocca continues as president and is designated chief operating officer; Philip Caldwell is named vice chairman, a new position. April 15 - Henry Ford II presides at dedication of Renaissance Center. October 8 - Ford Fairmont and Mercury Zephyr introduced. October 15 - CL-9000 line-haul diesel truck goes on sale.
I also looked at the pic and said right away it is later than 76--keep looking at the hood on the 359 in the forground on left--and the mayflower shaker 2 over from it w/the set back axle cabover--thought both looked early 80's-- BUT-BUT--BUT--the OP did say the internet pic said 76--not him and he was just posting a cool pic--and the last 3-4 posters--including myself--are older than DIRT and remember those trucks--and probably miss those day's--but IMHO the OP found a cool pic w/lotsa cabovers--that we are glad we don't have to drive any more--but the CL9000 was a hell of a step up from the crackerbox it replaced!