MMmmm....A case model would help. The crystal ball is broken :-D
I put two 92mm side by side on a Lian Li PC60, very tight fit. Still kept the lower USB ports
in place. I wish i had sanded the sides a touch and super-glued them together.
Once i swap-out the box i'm on now to the modded case. I will put a 120mmX38mm on
the front of this Lian Li Mid-Tower. All lower ports will be lost and a bay cover with ports
and such will be installed. Might even addapt the stock Lian Li ports to a 5.5" bay cover.
Go for it!!
Galvanized
EDIT: Cut a piece of cardboard to size and check placement or get real fancy and make
a box fan size. See what you got. Might have to move the HDD cage back an inch.