MGB's (incl V8's)with telescopics use the lower U bolt Plate as a mounting. The issue is the point of rotation of the axle relative to the position of the mount. On the Morgan it is placed so that it blocks rotation when the axle winds up. This is because the mount is parallel with the backplate.
The MGB fixing has the mount at right angles to the backplate so there is no restriction on axle wind up. This could be achieved on the Morgan by a bracket redesign, but it would need anti-tramps on the Roadster for sure.
