Rep Power: 747

hey guys... i don't know if this is really covered anywhere in another post, searched but didn't find anything that helps me. anyways a friend of mine just changed my master cylinder and the topic of rear disc conversion came up and well he said i may be able to get away with just changing the hub instead of the trailing arms,etc. does anyone know if this is true? any info would help. thx in advance!!! btw the conversion would be on a 94 Si.