excuse my ignorance please ... I have a 2000 F150 single cab long box 4.6 auto 4x4 . I want to change the gearing and instead of doing a ring and pinion swap I figured it would be easier ( For Me ) to just swap out the assemblies .
will a 9.75 or 10.5 directly replace the 8.8 ? I currently have 3.31 gearing and want to go to 3.73 or 4.10 if I can find it . have noticed many 3.73 in the 9.75 axle assembly than the 8.8 . and what years will directly swap into my truck ?? thanks in advance . Mike

 

97-03 9.75 will keep the spring perches in the same place and allow you to keep your rear wheels, but will require a shorter driveshaft.

A 10.25 from a light duty 97-03 f150 (the 7700's) I think has the same location on the spring perches but requires a different driveshaft and new rear wheels with the correct bolt pattern.