There is no transmission mount on a 54/55st 1/2 ton with manual transmission. Prior to '54, a transmission mount was used (and there was a frame cross member for it - there is no transmission-mount cross-member on the '54/55st frame)
Where are the rear motor mounts on your engine? In 54/55st (and later) they are below the clutch (bell) housing. The engine sat on the rear motor mounts. The 54/55st rear motor mounts are different from pre-54 rear motor mounts.
In prior years (on trucks) I think the rear motor mounts were to the sides of the clutch housing (producing a lot a shear stresses?).
In 54/55st, the frame cross-member rail for the rear motor mounts are, I think, different from earlier frames (maybe someone else has info on this). I think this was discussed in a recent posting on 53/54 frames.
Tim
