52" is right on the line between enough and not enough. The only way you will know for sure is to try it. I tried a 54 MotorGuide on my 22-2CCP and it was a little short. My current MinnKota 70AP has a 60" shaft and works great. Also the plastic (composite) shaft on the MinnKota is a lot lighter up and down that the 54" MotorGuide.
If you are looking at a MotorGuide, make sure you also get the Big Gator or Great White mount - the regular Gator does not work well with shaft lengths over 50".
Also, consider how the motor is going to reach over the "lip" of the bow. I worked with this a bit and wound up using the big MotorGuide quick disconnect slide-type mount with holes for stowed and operating positions. This gets the motor back and prevents dock (or whatever) damage when the motor is not going to be used. A quick disconnect pin and a clamping screw keep the motor in the desired location.
Here's how it looks moved back in the stowed position:
Here it is moved forward and deployed: [/b]
I move it forward for the first use on each trip, then leave it in that position until the end of the day, or if I just want to move it back to get it out of the way. Of course, you can also just take the whole thing off if you want - a nice security feature!
Don't forget the wiring details either - 4 or 6 gauge from the batteries to the motor, with a 50 or 60 amp breaker!
Hope this helps