Well the main reason I dont cut the body posts anymore is because I got caught out once on my TT-01 chasis. I cut the body posts down to fit one set of wheels and body but then when I put another body shell on with different tires all of a sudden the tires would rub or the front tires would rub when steering. Due to that sort of thing I leave them now because on Tamiya cars its a pain to try and track down a new set of body posts. Usually you cant buy them on their own and you have to buy a whole parts bag (like the whole "B" parts bag for the TT-01 for example).