IMS 4.7 or Safari tank?

Hello all,

Looking for opinion on the best of these two options for the X. Also, I read a post somewhere, maybe here about compatibility of some rad guards with the bigger tank. Can't seem to find it now.
thanks!
js

I am not an expert on the subject but, the safari holds about 3.5 gal of fuel based on some threads here.  Not sure what the actual amount of the ims is, but a gallon more fuel is a pretty huge difference.