looking through the rear hopper of the sf 36 refuse truck. block at rear of cab on left and no block on right. these also have the different inside cab studs.
http://img368.imageshack.us/img368/6673/refusetruck36sfcabxa5.jpg
different hopper doors, these are with and without the caution lettering.
http://img252.imageshack.us/img252/7307/refusetruck36sfhopmc2.jpg
carriage of the sf 7 refuse truck, high and low rear boss.
http://img107.imageshack.us/img107/4567/refusesfcarriagerh4.jpg
shades of orange and gray
http://img114.imageshack.us/img114/394/refuseqx4.jpg