Just made a deal for 3 cabs /frames that I can't after going thru the search forum figure out what these #s off the cab plate mean---2 0f these are heavy -one is a dually.Help please on telling me where to go ?the numbers are :dually-5QW-K 4061 the next is 21 GR -H 8764 the 3rd is 5 FRF 3459 thanks folks,sid stephenson