TheGreyGoose:
What's the difference?
What does a billet top cap do? How about water pick-up standard or low?
thanks Grey,
I had 1.36 gears on my Eliminator 300 Eagle, but it depends on your application. Those gears were a tad steep for my application, but the dealer bought it that way in case the purchaser wanted to put a cool charger, procharger or other blower on the engines.
Horsepower, speed prop pitch, Engine RPM are all factors in the equation. If you plan a high horsepower engine(s), you may want to go with the steeper gears so that you can still prop the boat for the horsepower to keep it within engine RPM limits. I am not sure but I seem to think that the steepest pitch prop available (production) from Mercruy is either 34 or 36". If your engine can turn these props at a higher RPM than your engine should turn, you should use steeper gears.
This link may help you see all of the variables and play with them interactively:
Prop Calculator
As far as the Billet top cap, the top cap is one of the weak points in the drive. But one of many. If you plan to put tons of torque and HP through the drive, you need a fully upgraded drive which would include a reinforced top cap.
The low water pickup relates to the X dimension of the drive. If the drive is set aggressively high, when you trim the drive the water intakes come out of the water. This is not a good thing for the powerplant, hence the introduction of the low water pickup.