Bravo 2 Gear ratio for 5.7 350

[Nitrostam]

Hello everyone this is my first post on this site. I apologize if this is in the wrong section.

I have a new project boat I am working on, its a theft recovery. I am no stranger to rebuilding the 5.7 engines or repairing stern drives

This is a Rinker Fiesta Vee 330, approximately 12500 Lbs and will be powered by twin 5.7 350's (shooting for 300Hp an engine.)

However in this case the boat is missing Both legs. So my question here is what gear ratio should I be shooting for on the new legs?

I intend to install Bravo 2 drives on this boat. Unless the Bravo 3's are a better option in this case??

Thank you for any input on this.

 

[alldodge]

The B2 is old school and while the B3 cost more, I think it would be better option

Would think 2.0 ratio would be what was original equipment for 12,500 lb

 

[Nitrostam]

Thank you alldodge I appreciate the response. I know the B3 uses the counter rotating props but what type of performance difference would you expect from the b3 vs the b2? Not looking to make the boat a speed demon but it would be nice to be able to run at a decent cruising speed.

 

[achris]

B2 runs a 20" (diameter) prop and is great for large hulls needing lots of thrust. These drives are good to about 50 knots, and 450hp engines (petrol)...
B3 is the counter-rotating props, but only 16" diameter (max). Strong enough for 525hp petrol engines, and 55 knots.

Usually the choice for a single engine boat is the B3, but as a twin, you could run the B2's (one as counter-rotating) and have the same sorts of benefits as a B3, without the cost.

For me, the advantage of the single prop (B2) over the twin (B3) in a twin engine boat makes them the choice.

 

[alldodge]

B3 is more efficient, guess that's why you hardly ever see B2's anymore on hulls much. Check out the manufactures I don't know if its even an option anymore. Getting a prop for a B3 is easy but the B2 are hard to find unless ordered. Would assume prop shops might have a couple around

There are 2 of the Rinker 330 here at the docks and both have B3's