Why would you want to do such a thing? Why does it have to be a B727?
If you are being hired to flya B727, they have to give you the required training anyway, and if they don't, you don't want to work for them, that's for sure, not if you value your life and your certificate.
If you are just bored out of your mind, you could find something more productive to do than attend a ground school for an airplane you won't be flying, and if you will be flying it, see the above.
So, what does that leave us? Did you tell someone you have B727 time? Or are you trying to get a jump on B727 training?
WTFO?