I just did mine horizontally last weekend- there is still enough of the shroud hanging down to cover a longish tranny cooler (not yet installed), and I didn't care about keeping the stock electric fan - I don't understand the rationale for having the stock electric after putting in the taurus fan....
having said that, i will now contradict myself and state that I am keeping an eye out for a smaller but higher efficiency electric fan to put in place of the stock electric. it seems to me to be a waste to not have any air being pulled through that section of the fan which still is fairly large even with the taurus fan in place. another alternative I am considering is to get another taurus fan just for the shroud, and hack the shroud onto the one that is on the XJ so that it covers the whole rad from side to side. I think this would probably make the biggest improvement in cooling.