If you really want a guitar tone that monstrous and ridiculous, the only way it'll fly ( from my first hand experience ) is to use a guitar cab AND a bass cab, but mix the volumes of the two. What I actually did was I used a preamp ( Line 6 PODXT in particular )'s two inputs each into separate channels of an 1800 watt poweramp, and for each speaker channel had one going to a guitar cab and one going to bass. On the bass side I had a 32 band EQ to boost/cut the frequencies I wanted. The guitar side was dry and I always had it louder than the bass side.
Nowadays I'd rather use the amplifier head of my choice and just use a Vector subwoofer guitar cab or something like that.