[TowerTalk] Using HDR-300 in HDX-572

[Dave Vore]

I presently have a HDR-300 and want to buy and HDX-572.  I see info that
says you need to have a small modification done to the HDX-572.  Can anyone
tell me what this modification is and does this in any way weaken the top
section of the tower?

I also heard that a Tail Twister is not to be used in the HDX-572.  Why
would that be?   If I can't use the HDR-300 that was to be my second
choice..

Thanks for any help.

Dave K8WW