how many hp outboard can I use

I have a Nordson 1960 its a cabin cruiser 6,5m long and 2,2m wide. I bought the boat without an outboard. How can I find out what the boat can handle. (The original builders dont even remember building this boat and there are only 3 that I know in Holland but all 3 different models) Has anyone a system for calculating the max hp

 

Hallo

I have an old broschure from Nordborg Baadebyggeri in Denmark.Your boat is in there, it says max 75hp

Dansan

 

http://www.geocities.com/howardstephenson/speedcalc.html

 

If the builder's book says 75hp, then it's probably 75hp.

If there's no spec plate or book, in Canada at least, you apply for a Single Vessel Capacity Plate. You submit about 50 measurements of the hull with a few photos, the appropriate bureaucrats plug them into a set of equations, out pops the maximum legal load and power ratings. You get a letter a month later saying you can use the boat; then sometime the next year the plate comes in the mail and you stick it to the transom. In Canada at least, that's about all there is to it. Designers may recommend lower power as they see fit but cannot mount higher power.