Chevrolet Blazer's History

          1969 
          Chevrolet & GMC Introduced the Blazer/Jimmy. Although not many options were
          available, the trucks came equipped with: 250 straight 6, 307 V-8,
          and the Infamous 350.  Transmission choices were: the TH350, 
          3 & 4 Speed Manuals (SM465).  The choices of transfer cases were
          limited mostly to: New Process 205's for Auto's, and Dana-20's
          W/the Manuals. The Driving axles were Dana 44's in the front 
          (which were used upto the date of production termination)
          and the GM Corporate 12 Bolt in the rear.
          Base Price:2,852.
          1971 
          Grille Change
          1972 
          Front Disc Brakes Added
          1973 
          Complete Interior and exterior redesign.  Wheelbase increased from 
          104 to 106 1/2"
          1974 
          Limited-slip Differential was available with full-time fourwheel drive.
          Factory installed rollbar became optional.
          1975
          The 307 V-8 was dropped.  The 400 V-8 became optional.  
          Electronic Ignition was added.
          1976 
          Fully removable fiberglass hardtop was replaced with a removable 
          fiberglass 1/2 cab behind the front seats, and fixed steel top (which also
          incorportated a rollbar) was standard from front seats to windshield.
          1977 
          Grille changed.  The 305 v-8 added as a option.  A "Chalet permanently 
          mounted camper option became available.  The corporate 10-bolt began
          to replace the Dana-44.
          1979
          High-back seats became standard.  The leading edge of the hood 
          was lowered slightly.
          1980  
          Grille changed.  The full-time four-wheel-drive system (NP203) was dropped,
          NP208 Transfer Case became standard with all transmissions.
          1981    
          There was a slight front clip redesign and a grille change.  
          Rectangular headlights appeard as did optional automatic hubs.
          1982 The 6.2L Diesel was added, and the four-speed TH700-R4 became optional 
          (it replaced the TH350).
          1983 The grille was changed, and the 250 inline-six was dropped.  
          The downsize Chevrolet S-10 joined the truck lineup.
          1985    
          There was a slight grille change.
          1987  
          Throttle-body injection became standard on all gas engines.
          1988
          The 305 V-8 was dropped.
          1989 
          Grille changed, and the serpentine belt system was added to all gas engines.
          1990  
          Rear-wheel ABS became standard.
          1992 
          There was a significant body & chassis redesign.  IFS replaced the solid-axle front
          suspension.  The NP208 was replaced by the NP241C and NP243 
          (Shift on the fly) Transfer Case.  A Getrag 5-speed manual replaced
          the SM465 four-speed.  Base price:$19,280.
          1993  
          Four-wheel ABS became standard, and the 4L60E replaced the TH700-R4.
          1995  
          Blazer/Jimmy name dropped from the fullsize truck lineup and
          replaced by the Tahoe/Yukon.  The S-10 designations were dropped
          from the downsize truck lineup and renamed CHevy Blazer or 
          GMC Jimmy.  A four-door version of tha Tahoe/Yukon was added to the
          fullsize lineup, but retained Tahoe/Yukon name.

Links

Chevy Blazer, a chronology

Chevy Blazer drawings