torsion mount repair caps???

I just took over a project car from my brother in law. Its a 71 duster with a 383 mag jammed in it ( was a 6 cyl.). It needs the new torsion bars but there is lots of rust under there so im gunna fix the torsion mounts so the mounts cab take the extra force. So, has anyone ever tryed the repair caps from year one???? or am i getting into something bad???