FYI don't ever recall that Allis Chalmers ever used a Datsun and/or Nissan engine. Worked for A-C from '67 thru Dec '81.
They used A-C engines, Continental flat head 4 & 6 cylinders, Teledyne Continental OHV Gas & Diesel 4 cyl, Waukesha and some Perkins models and 1 other make small HP flat head engine that I can't recall - then they close the doors in mid 1986 and sold the company to a guy in Ohio who operated as ACMH for a few years. In 1988 Kalmar bought AC material Handling and operated as Kalmar AC, then in 1999 Kalmar sold out to Komatsu and the lifts were sold as Kalmar AC model for a few years, then Kalmar AC brand name was dropped adn was changed to to Tusk Lift Trucks and somewhere around 2010 the Tusk name died the death of a ragged doll. That ended any linkage back to the original Allis-Chalmers name and brand (FYI Allis-Chalmers bought the Buda company and sold lift under the Buda name for some years). A road well traveled.