Hi Mike,
You have a few variables in that mix that are worthy of consideration.
Firstly - for its length - the hunter is HUGE. A lot bigger than one would expect. The boat Wickedgoogly built that you had asked me about was powered by a QD70 through a gear box to C/R S6 drives. Dont think any tue speed recordings were made though think it was in the mid 50mph range running a pair of 6517/3 props (Tiny props normally though with the overdrive they were plenty).
http://justaddwata1.multiply.com/pho...ls_Hunter_sold
A single inline zenoah would be pressed to get the Hunter over mid 40's would be my thought - especially taking into account overdrives etc. Having an Inline twin modified for notably more power would certainly help things - put you into the 12hp range and remain light. I should think 50's attainable.
An inline triple might give you more respectable speeds but I would think the life of the rear motor would be comprimised quickly - the little crank was never ment to have 12 or 13 odd HP passing through it - especially with the torque generated by the three firing positions Vs 1 or 2 for the other options.
A pair of inlines will fit that hull and move her fast but the stern drives will not appreciate all that power for long - plus you will have a heavy boat that you were trying to avoid in the first place.
You could always look at the QD70 or Mathe 70 but I think I would start with a single inline and if extra speed and power is needed have the motors modified.
Keep us in the loop on the build
