i would replace the belt driven fan with an electric one and gain the 8-10 hp . you can tap into the electric wires left over by the small fan
the small ones are for an extra boost when the ac is running
i have pictures on my website under modifications
http://www.ddmcse.com/turbo/modify.htm
fan setup costs around 100$ an easy 10 hp is priceless right ?
the plastic shroud costs around 150 i think
you need some kind of fans for sure