1972-1993 Dana Spicer Model 70 Rear Axles in Dodge 200, 250, 300, and 350 series trucks have a Bill of Material Number (BOM) that is either stamped on the rear face of the right axle tube or embossed on a Build Tag (red arrow) attached to the differential by two of the differential cover bolts. The BOM number is a 6 digit number beginning with a 6 plus a dash number (ex: 603651-3). They can be used to determine not only the axle model, but also what components the axle was originally built with. We often ask for this number to insure we provide you with the exact parts you need for your truck.
All 1972 to 1984.5 Dodge Model 70 rear axles will have a BOM that starts with "603". 1984.5-1993 axles will have a BOM that begins with "605". Each different BOM number signifies an engineering part change which may be minor or major and may involve one or more parts. The dash number indicates the axle ratio and differential type (open or locking). Unfortunately, these tags are often missing on trucks that had prior differential service.
1972-1993 Dodge Dana 70 Rear Axle Bill of Material Numbers (Motorhome and Van BOM Numbers are italicized):
1973-1975: 603242, 603285, 603341, 603346, 603377, 603378, 603515, 603547
1976-1979: 603396, 603649, 603396, 603547,603651, 603652, 603653, 603695, 603696, 603841, 603872, 603955
1980-1984:c 603653,603916, 603918, 603955, 603995, 603997, 603998
1984.5-1985: 605158, 605192, 605214, 605215, 605235, 605269, 605270
1986: 605158, 605235, 605269, 605270
1987: 605311, 605313, 605513,
1988: 605311, 605313, 605386, 605513
1989: 605311,605312, 605313, 605373, 605386, 605407, 605408 ,605513
1990: 605311, 605312, 605313, 605373, 605386, 605407, 605489, 605513
1991: 605508, 605509, 605510, 605511, 605512
1992: 605508, 605509, 605510, 605511, 605512, 605514, 605522
1993: 605508, 605509, 605510, 605511, 605512, 605514, 605522
