cmc vs factory tilt and trim

Considering adding a t/t system to my 1648 with 2012 merc 25 efi. From my understanding, the factory does not allow kick up, but the cmc does. Cmc should be a little cheaper, but harder to install. Also, cmc adds 5 1/2'' set back. What will this do to my boat, and will it require a prop change? I do know that my cover will not fit with an additional 5 1/2' st back, so I would also need to buy a new cover. All help is appreciated.

Jeff

New prop depends on height changes you make after installing the plate. No need at all to change the props if you just go up around an inch to inch and a half. Way to measure is to make the cavitation plate parallel to the bottom to the boat (use a straight edge or anything dead straight and place it on the boat bottom extending past the full length of the cav plate or place it on the bottom of the plate and mark it against the bottom of the boat. Note that there is no set rule on how far up you can go with how far back you are. Somebody is sure to chime in with an old wives tale about half in. up with every inch of set back....not true.
Later on you can move the engine up to the limitations of your propeller and then get into another prop that offers better performance at elevated heights and do your testing all over again. Make sure when you move it up that you are still picking up cooling water but at the low starting heights I gave you there should be no issues.