Have to say ya must jacked that sucker well up to cause that!
Why not just put a new stirrup to the right of the crack and then simply use a gang nail plate over the crack - both sides if you can get access, but one would be enough. Or even with bit of 90x45 HW short spacer on its flat and a stirrup right underneath the crack.
Advice from me on this forum is general and for guidance based on information given by the member posing the question. Not to be used in place of professional advice from people appropriately qualified in the relevant field. All structural work must be approved and constructed to the BCA or other relevant standards by suitably licensed persons. The person doing the work and reading my advice accepts responsibility for ensuring the work done accords with the applicable law.