Found this posted by a guy named VaderSS
"" the 9C1 Caprice package consisted of;
thicker sway bars
stiffer frame bushings(in all locations, civilian cars did not recieve lower bushings in all locations)
more accurate speedometer
silicone coolant hoses
bigger lower ball joints(later cars)
5.7L engine available(in earlier civilian cars, 5.0 was largest available)
high output alternator
high speed heavy duty cooling(bigger fan motors and radiator)(Towing package had engine driven fan, Low Speed HD cooling(this knocks 10HP off)
heavier steering feel
quicker steering ratio(earlier cars)
external engine oil cooler
power steering fluid cooler
exra wiring provisions/hookups
1st gear block-off plate
heavy duty wheels
"V" rated tires
high speed drive-shaft
WOT A/C cut-off
heavy duty transmission
many esoteric options were available, from light bar wiring and moulding delete on front doors, to a heads up night vision system.
The Impala SS and earlier Caprice LTZ got most(but not all) of the handling and performance upgrades of the 9C1 packages, and got some things that did not come standard on the 9C1.
Some examples are that the early LTZ did not get a 5.7L engine, but the Impala got the 5.7 when it was not standard in the 9C1. LTZ and Impala had regular hoses and were missing the frame bushings that the 9C1 got.""