Well I would say cut and narrow the torsion tube 3\" per side, bevel the tubes and weld it back up. I would probably put a sleeve (piece of pipe with the similiar o.d. as the i.d. of the torsion tube) in there as a sort of backing plate to get \"maximum penetration\"

when welding it back together. I would also clamp on a piece of angle or channel to make sure the tubes are straight when I tack it together. Leave it tacked and mock up the suspension before welding. Measure twice. Weld once. I take it you have the springplates with the longer spline tube and the 21 3/4\" torsion bars. Disclaimer : Keep in mind I have not done this before but have researched it for a future project so you might want another opinion or suggestions. Let us know how it goes. By the way, where is Rosedale, B.C.?
Good luck
Jeremy