It's a direct bolt on. It will be harder on the drivetrain though. The best mod you can make is the Robinson Racing slipper. That way you can set it correctly and keep the strain out of the drivetrain. Then upgrade diffs and shafts as you break them.
also you'll need the 2.5-3.3 upgrade kit if you have a rotory carb, as the 3.3 is slide I had that problem,it also has the nessceary exhaust manifold n pipe part # 4900 I think.