martyn, You wont need to change the exsursted m8 4x4 ones fit swd but 2wd wont fit the 4x4 ect ect I cant belie you want to swop 4wd to 2wd Stg3 on the 4x4 box should be fine to a point so i have heared ect
But 2wd is fun (just not as fun in the wet