Found this on the Kawasaki Forum and thought it would prove useful on here.
Now some basic information regarding the bikes covered.
98/99 ZX6R "G" Model
00-02 ZX6R "J" Model
Now, for the most part, here are the differences comparing the "G" to "J" Model bikes.
-Upper Fairing only had 1 headlight, used different windscreen, and air ducts, but the entire rest of the bodywork will swap out.
-Used a different gauge that is wired differently.
-Gauge stay/ Fairing stay was different and not swappable
-Swingarm is the same, just the "J" Model had a "Knife Edge"
-98-99 forks were spaced about 3/16" narrower than 00-02 and were 1 1/4" longer for over-the-clamp handle bars.
Fender mounting is slightly different, but you can go either direction with some minor modifications to the fender.
Brake calipers will bolt up (virtually any ZX caliper will fit except the radial mount style) , supposedly the 00-02 had less fade.
-Front Fenders were slightly different.
-Charging system was different, as was the ignition system, so for people looking to do a engine swap, either will work, but you must use your existing pickup rotor, stator, and harness including coils.
-The "bottom end" of the engine was the same, but from the cylinders up the engine was different internally.
-The gas cap had 5 bolts instead of 3
-Steering Head Bearings were tapered roller (timpkin) instead of the roller ball bearings used on the newer ones, either can be used with the correct races.
Now to compare the "J" Model to the the ZZR600
-Simply put, the ONLY difference was the fairing stay, and it eliminated the "bird cage", and can be used on the "J" Model, it will work on the "G" model as well, but only if you have the "J" Model Headlights and upper as the headlight mount is different and the overall shape of the upper is different.
So to put all this in simple terms, the 00-02 ZX6R "J" is IDENTICAL to the 05-08 ZZR600 with the exception of the fairing stay which can be used, so ANY PART FOR THE 05-08 ZZR600 WILL FIT THE 00-02 ZX6R "J" AND VICE VERSA!
Now for a little more info regarding other bikes.
-05-10 ZX6R Wheels are all the same
-98-04 ZX6R Rear Wheels the same
-05-10 ZX6R Front Rotors are all the same
-98-10 ZX6R Rear Rotors are all the same size and bolt pattern, they just went to a "Wave" rotor in 2005
-98-10 ZX6R Front Sprockets are the same CHECK PITCH 2003 went to 520!
-98-10 ZX6R Sprockets all have the same bolt pattern, 2003 they went to 520 from 525
-98-04 ZX6R Mirrors are the same stud spacing
-05-10 ZX6R Mirrors have the same stud spacing
-05-08 ZX6R Swingarms are the same, in 07 they changed the look slightly, but still the same bolt spacing and sizing.
-03-08 ZX6R Clip-ons are all 50MM and work with each other.
-03-06 ZX6R Top Triple Clamps are the same just look different
-03-08 ZX6R Forks the same dimensions are the same, just 03/04 had smaller rotors so the caliper mounts were 10MM shorter.
-03-10 ZX6R Calipers all bolt up, 03-06 ZX6R Exactly the same 07-10 ZX6R went to Nissins which are a much better caliper.
-98-10 ZX6R Bar Ends all the same
-00-10 ZX6R Gas Caps interchangeable
-06-10 ZX10R Front Wheel same as 05+ ZX6R
-04-10 ZX10R Rotors the same as 05+ ZX6R
-98-03 ZX9R Rear Rotor same as the ZX10R/ZX6R
-98-04 ZX6R Passenger Pegs the same
-05-10 ZX6R Passenger pegs the same
-98-10 ZX6R and ZX10R Rear Calipers are all the same
-98-10 ZX6R Cush Drives are the same piece
-98/99 ZX9R Front Rotors are he same as he "G" and "J" and ZZR600
Now for the Parts Swapping Information!
-03/04 ZX6R Rear Wheel is a direct bolt on, the front wheel needs the 05+ ZX6R rotors to be used. Always use the spacers for the generation wheel you are swapping for a direct swap.
-05+ ZX6R Rear Wheel can be used, but is skinnier and needs either new spacers made or spacers added to what is there, the front wheel is a direct swap, but the newer rotors are needed as well.
-06+ ZX10R Front Wheel is the same situation as the newer ZX6R.
-00-02 ZX9R Wheels fit, but the rear is 6" instead of 5.5" and will need spacers made and the chain lined up, but the front is a direct swap.
-03/04 ZX6R Swingarm is the same as the 98-02 in size, but it has an extra tab or two for more Hugger Choices.
-05-08 ZX6R Swingarm bolts on, but the corresponding wheel needs to be used for it to be direct bolt on, also a longer chain and brake line is needed.
-02/03 ZX9R Braced Swingarm will bolt on with minor machining overall width and bearing swap out. Luxeryliquidator knows the details, PM him for details. not as easy as the 636 swap, but different!
-09/10 ZX6R Swingarm, i have not swapped or seen it done, but i had heard of people doing it on the 05+ bikes, and if it can be done on them, it can be done on ours just as easy, and it seems like a simple swap for the most part, but no definite information on it yet.
-03/04 ZX6R Shock is a direct swap, slightly better then the 98-02 shock.
-05-08 ZX6R Shock will bolt up with either grinding of the lower mount of the shock, or swapping over to the corresponding linkage.
-04+ ZX10R Shock is the same deal as the 05+ ZX6R.
-03-08 ZX6R Forks can be swapped onto the bike, but here are a few things needed to be done,
Press the Steering Stem from the stock clamp out and then into the 03-08 ZX6R Lower Clamp
Then a Bushing will need to be made to go into the Top Clamp and fit around the 98-02 Stem, this will prevent twisting of the front end.
The Top Clamp will need to be trimmed down in the Ignition Switch area for the original switch to be used, and you will lose the function of the steering lock at full wheel turn
With the swap you can use your stock wheel and spacers, but you must use your stock rotors as well due to backspacing of them.
You will also need to drill new holes in the new clip-ons for the locking pins for the throttle housing.
03-04 front forks and triple trees
-09-10 ZX6R Forks should be the same deal, i have yet to try it but it should be, but in 2009 they went to 51MM forks, so the correct clamps need to be had.
-04-10 ZX10R Forks also should be the same thing except the 2004/05 ZX10R Front axle is smaller, so the correct wheel is needed.
-ZX12R front end will bolt up with the only mods being, omitting a top locknut(which the top tripleclamp holds tight) a simple bolton, with gains of inverted forks/tigher springs/oversized brakes.
-03/04 ZX6R Header will bolt up, either aftermarket or stock. Doing this will open a wide variety of slip-on options including highmount pipes!
-98+ ZX9R Bolt on Cans will fit right up the the ZX6R
-03/04 ZX6R Engine will bolt into the frame with the exception of the front 2 engine mounts, which are critical, but with some welding and fab it can be done, i have done it. Remember if you do decide to do this, you will need all the electronics off of the bike along with the tank and fuel pump, and you will need to make the tank fit as the mounts are quite different, but does line up decent.
-03/04 ZX6R Clutch Cover and Ignition Cover bolt on.
-03-06 ZX6R Radiator will bolt up and the hoses line up great, the 05/06 ZX6R does not have a fan switch built in, and they are physically smaller then the original, but work fine, especially for fairing swap when you need a smaller one.
-03-06 ZX6R Pistons fit, the "RR" Pistons are forged and 1MM smaller then the "636" Pistons. Use the 98/99 ZX6R "G" Cylinders, and bore them sense they are steel, and have a cheap Big Bore Kit, The 98/99 Head cant be used though, the engine needs a 00-02 Zx6R "J" Model head, or 05-08 ZZR600.
-98-02 ZX6R Cams interchange, they were different, but can be swapped, some believe there is a performance gain in using the "G" Exhaust cam.
-98-02 ZX6R and 05-08 ZZR600 Carbs can be swapped with minor jetting changes throughout the years, but they will bolt on no issue.
-91-95 ZX7R carbs can bolt on, with some tinkering. Rerouting the throttle cables, with an inversion of the twist assembly.Using larger clamps, heavy modifying the carb plate and alot of patients doing the jetting unless you have access to a really good engine brake dyno, with fans for ram air replication!
-03-06 ZX6R Gauge will swap over, it has the same plug, but does need to be rewired. The 05/06 ZX6R Gauge speed reads 90% off and a speedohealer is needed to correct the issue
How To: 03-06 636 gauges on a G and J model 600
-07-10 ZX6R Gauges will swap, but not only do you need to rewire the plug, but you need a new plug as its a different shape and size. "Shvr" has done the swap.
-03/04 ZX6R Speed Sensor is the same.
-03/04 ZX6R Fuse Box plugs in, exactly the same.
-00-03 ZX9R Headlight is the same as the "J" Model and the ZZR600, but that is the only piece of the bodywork.
-98/99 ZX9R Headlight, the single one, should also be the same as the "G" headlight and mount with no problems.
-98-03 ZX9R Rearsets will bolt on and are identical, this gives you a few more options with the aftermarket or crash replacement.
-03/04 ZX6R Heel Gaurds on the rearsets are a direct bolt on.
-03-10 ZX6R Clutch Perch will bolt up and work fine, but you need the correct lever for it.
-03-10 ZX6R or ZX10R Front Master Cylinder will work as well, but with the 05+ ZX6R you will need new brake lines because its a radial master, and works much better.
-03/04 ZX6R Subframe can be swapped over, there is a bit of welding, more details here: Project"636"tail swap.Final VERSION!!
-05/06 ZX6R Subframe can be swapped over as well, there needs to be brackets made, and some time but it can be done. my undertail project for 00-02 zx6r so far........
-07/08 ZX6R Subframe i have recently swapped over, there needs to be brackets added to the upper mounts of the subframe, and then brackets made and bolted or welded onto the frame for the lower mounts, the subframe is skinnier and offset for the undertail exhaust. On top of the work to get it mounted, there is a bit of working making cover panels for it to make it look right because its designed to have them there.
-09/10 ZX6R Subframe i have not done or seen in person, but it looks like a pretty simple swap for the most part, and it looks cool, but no info on it yet.
-06-08 R6 Tail swap, bolts right on the upper subframe mount, but you need to make a lower mount which can be easily bolted on and be adjusted for correct tail height. Seat lines up with tank with some work, but the Subframe bolts up pretty easily. Problem i ran into was there is not exhaust hanger, but other then that, its a very different mod, and its actually a quite simple bolt up with some minor drilling and simple tools can have it done in a few hours. If you are attempting to do this, then I would hope and assume you have some wrenching skills, if not, it may be hard.
-Nothing other then the "G" and "J" and ZZR600 stuff will "Bolt Up" but here are a few sets that swap with some work.
-03/04 ZX6R Bodywork lines up nice, but the entire ram air system needs to be changed, and you need to make new dash covers, and buy all of the corresponding pieces including headlights etc.
-05/06 ZX6R Bodywork, same exact deal as the 03/04 stuff as it requires all the same mods to work.
-98-02 ZX6R and 05-08 ZZR600 Bodywork is ALL THE SAME MINUS THE UPPER FAIRING, which means you can use a 98 side panel with a 02 upper or whatever combination you want, the 98/99 Upper and the 00-02 Upper bolt up the same, but are shaped a little different and use different lights, and windscreens.
IF ITS NOT LISTED IN HERE, IT MOST LIKLY DOES NOT FIT, BUT I MAY HAVE MISSED A FEW THINGS. BUT USE YOUR HEAD, LOOK AT THE LISTS ON WHAT PARTS ARE ALL THE SAME AND IF THEY FIT YOUR NEEDS!!!! PLEASE DONT ASK WILL A ZX9R ENGINE FIT, ITS NOT LISTED, NO IT DOESNT, AND PLEASE READ THAT THE ZX6R FROM 98-02 AND THE ZZR600 FROM 05-08 ARE THE SAME WITH THE EXCEPTIONS LISTED!!!
HOPE THIS HELPS SOME PEEPS OUT WITH WHAT FITS AND WHAT DOESN'T