here`s how I would fix it. take 2 pieces of alu or steel ( like maybe an inch square ,doesn`t really matter ) tack weld them together and drill a hole through the seam, the size of the tube, so you can use it to clamp the tube up side down in a vise right above the ridge that lays on the block surface ( hope that makes sense ) Heat the part that goes in the block and use a round tip punch (or the backside of a drillbit )