What would Mace recommend as the easiest/cost effective way to increase torque? I tow a 4.5M tinny (boat), and would like to get better fuel consumption on my VZ Alloytec V6.

While we have many performance products to suit the Alloytec, given your torque requirements, our manifold insulators would arguably be your best choice. For more information about these available products, please check out the links below:

COLD AIR INTAKE MANIFOLD INSULATOR ALLOYTEC VZ-VE

http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/MI603

25MM COLD AIR INTAKE MANIFOLD INSULATOR ALLOYTEC VZ-VE

https://www.maceengineering.com.au/epages/mace.sf/en_AU/?ObjectPath=/Shops/mace/Products/MI603/SubProducts/MI603