I realize this is an old thread, but in case anyone else comes across it, L5740 grand cab models come with the gear already install in the case, adding the mid PTO is as simple as removing the case cover under the machine and installing the mid PTO. I just installed a mid PTO on my Grand L5740 HSTC Cab and it was very easy (you do have to drain all of the hydro fluid, so be prepared with 10 gal of UDT.
From my understanding the non cab models do not have the gear factor installed and the process is much more involved.