Layout
FR layout 

Engine
235 cu in (3.9 L) Blue Flame I6
283 cu in (4.6 L) Turbo Fire V8
348 cu in (5.7 L) W-series Turbo Thrust V8
 
Transmission
3-speed (close-ratio) manual
3-speed overdrive manual
4-speed manual
Turboglide auto.
2-speed Powerglide auto.
(Corvette-type) 

Chevrolet Impala on Wikipedia

Chevrolet Impala tech specs on https://www.automobile-catalog.com/