not that the rear is not necessary, the trouble of doing the rear makes people overlook the job, unless you don’t need an e-brake cable( wich you do for safety) you need to redo the e brake cable, need to take q45 rear hub setup somehow fab it up to your 240, get ebrake cable extension kit,
Same work needs to be done on a z32 rear brake conversion for 240sx…
meaning new rear suspesion will be necessary
this is why the front is done often, but not the back.