Got the retro designed ROPS for my L245DT. Working on getting it installed now. The "destructions" say the center arm will be set back a little with the ROPS installed. I just hope it is not a "little" enough to make me buy a shorter center arm.
Aquaforce -
What the instructions try to tell you is that you will be removing the current place that the 3 point hitch attaches to (2 angled pieces with holes in them), then installing the ROPS in the same place, then installing the same 2 angled pieces back on top of the ROPS.
If your ROPS is like the one I got for my L185 it is rectangular about 2.5 x 3.5 inches. If memory serves me right, the 3.5 inches is the distance the ROPS will extend back to the implement. Therefore your top link will be about 3.5 inches closer to the implement.
A few hints for installing the ROPS -
Make sure it fits together well - mine had one side a little longer than the other so it needed to be persuaded a bit.
Ensure you understand which holes the long studs go into - I recall they go into the same bolt holes the angled pieces were bolted to. The instructions can be a bit confusing there.
Ensure the holes at the bottom of the ROPS are clean and spray some type of lube into them before starting the installation (or use some method to clean them/remove rust).
Leave all the bolts and studs loose as you can when installing the ROPS and get every bolt started into the tractor, insure they are started correctly and not cross threaded. (the lower ones are tough since you need to lift the ROPS to align the holes in the ROPS with the tractor - use a jack)
Leave the splice at the top of the ROPS loose also until you get it aligned. That was the secret to getting mine installed.
If you have a second person (or third) it will help. The thing is just too heavy and odd shaped for one person to handle. I did it by myself but had to rig some lifting slings to the top to hoist it and it does not lift at the right angle to easily install.
I ended up putting half on very loosely, then installing the second half and the splice plate and fighting to get it together. It can be done with one person, it just takes longer and it a bit frustrating.
I think I wrote a post about it and will see if I can find it and link it back here. Found it - see this link:
http://www.orangetractortalks.com/forums/showthread.php?p=51566#post51566
Oh - I did not have to do any mod to the top link for my implements but never really thought about it being "longer".