I know that the question is EDGE PRO to LO/PRO, and my answer remains the same. Yes, I'm 90% sure that it can be done without modifying the trem cavity. The trem cavity on EDGE PRO guitars is HUGE in comparison to that of a LO/PRO or EDGE guitar. If my thinking is correct (which I will go to guitar center and buy a guitar tomorrow with an EDGE PRO trem, then replace it with the LO/PRO and EDGE trems to prove it) you should have MORE THAN ENOUGH ROOM TO INSTALL A LO/PRO.
Okay.... although I was already 99% sure it was the case, I measured my bodies trem cavity against that of my factory JEM7V. My trem cavity was actually smaller by 2/1000ths of an inch (about the thickness of a sheet of notebook paper) in both left to right and front to back. Not enough to make a difference in my test. If anything, I guess it should mean that you would have better results in a real Jem Body.
In order to prove that it can be done I have installed an EDGE PRO into my JEM7V, with NO MODIFICATION. I will string it up in the morning, and make a video of it. PROVING that it can be done. Sorry Rich, but YES. You can install an EDGE PRO into a LO/PRO EDGE cavity. I don't know why anyone would ever want to replace and EDGE or LO/PRO with and EDGE PRO, but if you did want to, it could be done with ZERO routing or modifying.
Now to further clarify, I'm not saying that you have 100% pull up on the bar, but you do have MORE THAN ENOUGH for the average trem user. Probably like 40-50% of the pull up. As far as a dive, my trem arm actually hits the pick guard before it bottoms out in a dive.
I feel bad doing it to my Jem, but I had to do it to prove that IT CAN BE DONE. As you can see in the pics NO PROBLEM. As you'll be able to hear in the video, you can get plenty of play room.
Here are pics again.....
Here are some other freebies:
Jem555 has so far accepted every Ibanez trem I own, and is fully functional:
TRS (I think that's what the one it comes with is called?)
Jem7VWH will accept:
EDGE PRO (with minor limitations on the pull up)
I can only guess(I haven't tried installing them on ALL Jems), but I'm going to say that the JEMS with AANJ neck joints will have similar results as JEM7V.
So I guess to close (because I'm not going to argue this with Rich or anyone else), I would say TRY IT! The worst that could happen is it doesn't work AND THEN you can route it till your hearts content. However, if you just start routing because SOMEONE told you to, you might be risking UN-NECESSARILY damaging a guitar you love.
Good luck, and I'll post the vids tomorrow (if anyone cares).