Fan clearance

[PBDBLUE]

I did some high altitude single track last week and in the really technical sections was having overheating problems on my 03 WR450. I'd like to add a SPAL 4" fan but with the IMS tank it doesn't look like there will be enough clearance. Anyone know if the Acrebis 3.3 tank has more clearance between the radiator and the tank? The other option is to put the fan in front of the radiator but it would seem pretty vulnerable out there.