California emission mods, ICU troubles, 89 100

[David Conner <conner@cfm.ohio-state.edu>]

What are the differences between cars sold in CA and those shipped to the
other States?
I have two similar cars, w/ the same engine, etc. but discovered the 89 100
non-turbo is a California car.
It never had the same feel in driving it as the 87 5KS...less pep overall.  
I'm having trouble with the Ignition computer (ICU) in the CA car and in
checking the part number for a replacement, Linda @ Carlsen tells me it is a
CA part, therefore a CA car.
 All the local dealer could tell me was that the car has an ICU for the
wrong model year in it.  
It's not clear exactly what the problem is with this ICU, but it seems to
have the timing way off.
Can I simply put an "other 49 states" ICU in the car, or would this create
problems?  It would be much easier to find a used one if I could go this route.
What would the differences be w/ the CA ICU?
Does IA (Ned Ritchie) sell modified ICU's or do they take the one out of
your car and modify it? 
Would they be able to diagnose/repair and hopefully improve the
malfunctioning unit, as an alternative to replacing it with an "other 49
states" version to get even better performance?
Thanks for any help in understanding how all this works.
bye,

 
David Conner  Columbus, OH   614-847-1268
'87 5KS,  '89 100