forgetting one thing..
it really makes no sense to run a larger line then the fitting on the compressor is. if u look for more storage of air then a lg line is ok.. IF u want flow... then make sure the fitting from the compressor is the largest it will take. the smallest part of that line is an "orfice" and u can not flow more air then that part will allow. and thats the ID of any part on that line.