The problem with the single fan set ups is that in order to move a large volume of air, they have to be thicker than a comparable dual fan set up to get the surface area. This puts the fan motor smack dab in front of the blower pulley.
If my Taurus fan won't work, I can guarantee an even larger Mark VIII fan won't either.
If my Taurus fan won't work, I can guarantee an even larger Mark VIII fan won't either.