Im trying to get a trolling motor from minnkota and need this measurment

It would vary from boat to boat. My guess is a 45” trolling motor would be plenty. 

I had a 1448 before and a 45” is more than enough. 

Personal I would go with a 52" 

Take the time to get an accurate measurement. A motor that is too long will work, but if you run in shallow water, the head will be so high it will be in your way. I had two boats and would move my Terrova trolling motor between boats. It was too long for my 16’x48” jon boat. The front deck on the boat wasn’t huge and the motor head sticking up always bothered me.

I had a 45” on mine