HELP! exchanging exhaust with race kit

[wezo]

Is a long story, but basically i have an 04 XB9s with a factory exhaust. At our local Harley garage is a xb12r with a race can which has been imported from the US, (i'm in NZ). The imported xb12 needs an original exhaust to get compliance so i have the opportunity to do a swap. My standard exhaust for the race cans. It appears the exhaust mounts are identical so the swap should be straightforward.
but, do i need the race ECM or can i get away with my factory one? Or, can i take the race ECM off the Xb12r and put it into my XB9s? Will the Xb9s fit in the XB12r? What about the filter? Same deal? Help appreciated.

 

[Thorivola]

the mechanical parts are straight swap (filter and pipe), but the ECMs have different mappings on them AND the muffler on the 9 is not interactive (there is no internal valve) so the 12 won't run quite as well no matter what you do

the ECMs are the same size, but the 12 has a heavier injection mapping and inversely for the 9 based on displacement

you can get maps for both ECMs to flash to stock settings, but the 12 race ECM will not work on the 9 without being changed to the 9 flash

if you flash the 9 ECM to 12 stock mappings and put it on the 12, then flash the 12 race ECM to 9 race ECM and put it on the 9, you'll be set

in order to get the 12 to run at stock though, it would require an interactive muffler