Steve,
On the rear crossmember, several fit between the rails from the various sizes of trucks, they just mount different. I found when building Brads 1 ton panel, that someone cut out his crossmember. I found one out of a 2 ton to replace his 1 ton's cut piece. Not sure, but I think it dropped a little lower which helped me out when installing his V-8. The good part, it all looks factory, nothing homemade looking. Regardless, I'm sure a factory one could be modified to work,
Scott