Take your original radiator to a shop, they can swap/move the inlet and outlet for you pretty easy, it's usually not too expensive. I don't know if that's enough radiator to cool an LT1, though. A good shop should be able to help you there, too.
Ooops, I'm thinking CJ stuff. Does it have plastic tanks? if so, forget I even answered. Still, a good shop may be the most affordable option, find something that works. Maybe adapt a heavy duty V-8 CJ radiator with metal tanks.