Noticed your owners manual specified LV 75w GL-4 for (LV being light viscosity), so this might be what you need.
http://www.torcoracingoils.com/products/productview.aspx?id=e4ed8abb-6d43-4c67-9322-f6eca3591760
MTF MANUAL TRANSMISSION FLUID
>>Description
MTF is a special
light viscosity, low friction oil with superior load carrying and wear protection properties. It is formulated using the highest quality petroleum base stocks and unique additive systems that focus on thermal stability, shear stability and shock load protection. MTF is treated with anti-oxidation, anticorrosion and anti-foam to reduce fluid degradation and increase life of all drive components.
>>Features
>Superior load carrying and wear protection
>Improves power throughput
>Quicker shifts and smooth operation
>Superior shock load and extreme pressure
wear protection
>Excellent anti-rust and corrosion protection
>>Application
MTF can be used in manual transmissions, transaxles and transfer cases where an ATF or GL-4 light viscosity oil is recommended (for axles with spiral bevel gears operating under moderate to severe conditions). Highly recommended for racing and performance street applications.
MTF is specifically recommended by Mercury Marine® for use in the MC Six Dry Sump Outdrives.
Improves power efficiency and rust protection for outdrive units.
MTF also exceeds performance requirements for Lenco® transmissions.
MTF is formulated to Torco’s proprietary race specific additive technology.
Exceeds API GL-4 performance requirements. Intended for performance and racing applications.
>>Typical/Test Data
Description ASTM# MTF
Appearance Visual CL/Amber
API Gravity D-287 30.1
Lbs/Gal Tables 7.29
Specific Gravity @ 15.6/15.6°C D-1298 0.8756
Viscosity @ 100°C D-445 8.35
Viscosity @ 40°C D-445 53
Viscosity Index D-2270 135
Pour Point, °C D-97 -20
Flash Point, °C D-92 210
Fire Point, °C D-92 220
Copper Corrosion D-130 2A