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extension boxes or shorties which is better

Old 12-02-2011 | 07:42 PM
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From: new port richey / cape coral fl.
Question extension boxes or shorties which is better

thinking about either one, but can't afford both. What would you go with and why, on a 38' cat with t-700hp, bravo 4blade 34 pitch, top end 110, crusies nice at 75 at 4000rpm, would like a higher cruise speed
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Old 12-02-2011 | 08:17 PM
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From: St Amant La
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if the boat has a notch in the sponsons then no need for boxes but shorties would help


no notch then go with boxes
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Old 12-03-2011 | 12:11 AM
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boxes r a thing of the past with current prop tech and changing gear ratios.

while doing the above could get ya considerable higher top end speeds....it may kill your cruise efficiency. the cool thing is the above can also be swapped in a parking lot to test.
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Old 12-03-2011 | 04:15 PM
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Shorties will NOT do anything for cruise speed, more for top end as the other poster mentioned. Once you put them on you will then have to try a bunch of different props to find the "sweet" spot if they even help you, Smitty
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Old 12-03-2011 | 07:40 PM
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before making a change i would work something out with a prop company you are going to use! i have no idea how herring is working things these days and lake X has been gone for so long that most don't even know what it was. point is buys a set of SM lowers maybe the cheapest part of the equation!

as a rule....don't go looking for more speed on a budget. it never works out.

ps....ditch the the 4 blades! they are brutal on drives!

pss...find JBS on the forum here...i think he still has some props in your range prob 1/2 dozen or so left from our super v days...maybe by the lot of them for a good deal. there r 4, 5, and 6 blades.

psss....there were 3 sets of 4 blade 34 bravos, if he still has them? one set is LIKE NO OTHERs. prob one of the last sets Dennis Cavanaugh ever made and they are marked 34SW's.
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