I'm looking at doing some basic bolt ons to my GSR and I see several sites that list parts will fit only 94-99 GSRs. Mine is an 01. What are the differences in the 99 and the 01 GSR that would make these parts not fit?

For example, I'm looking at putting on a Comptech High Flow Catalytic Converter and Comptech lists only 94-99 for this cat.
I also see some suspension components are like this as well.

Any ideas?

 

there is a difference in cat length, and you are obd 2b, so basically suspension whise 94-01 will fit, engine minus header, down pipe ( which u have to worry about) will fit, ECU stuff very limited with obd 2b, the reason why they only list the high flow cat is because those motors are not obd2b, u can get a carsound one, instead