I am trying to find the differences of the impala ss and the z28. are they the same or totally different? "performance wise"

 

It still uses the same 350c.i. V8 that the Camaro/Firebird/Corvette uses so the aftermarket engine parts will carry over to the Impy platform as well. Things will start to differ with the exhaust, steering, and suspension components.

 

The big difference is the weight. Here are some links for your viewing pleasure.

http://consumerguideauto.howstuffwor...mpala-ss-4.htm
http://consumerguideauto.howstuffwor...t-camaro-4.htm

 

This article has the details on the engine differences:

http://www.automotiverebuilder.com/ar/ar99928.htm