73F100Shortbed
That's how we roll!
I would do the shift kit at the same time personally this way it is covered in with whatever warranty they are giving you on the trans. Adding it later they may charge you more labor and then the added cost of trans. fluid, etc. Probably cheaper now to do it and they can't say later that adding it voided your warranty. But if he is already firming up the shifts maybe just leave it at that if you need to save money.