The grace opti-mod does get rid of the word clock out, I don't think there is any way around it.
That said, you don't need an actual word clock out to sync the 722 to a V3>D50 rig -- I did it all the time using the regular coax/spdif out of the V3. V3 optical out to the D50 with what you want to record on those channels, then V3 coax out (or AES out) to the digital input of the 722/702. Set the 722 to take analog input (I think the choices are digi-in, analog-in, or auto-select which selects the digital input if it is present or analog otherwise). Something like that anyway, it's been awhile since I owned the 722 or 702 (owned both). You can't use the auto select option, but if you put a regular coax/spdif output attached to the digital in and select analog input on the 722, the 722 will strip the clock info from the incoming spdif signal and use it as it's clock, so the V3>D50 channels will be synced to the channels you're recording on the 722. If you do this, an "L" or something like that shows up on the 722 LCD.
I don't know if this works to clock sync with a 744, but it works with both the 722 and 702.