You'll still have to modify the tunnel to make either a 727 auto or a M/T work. The mopar m/t's used that mess of brackets on the side of the trans for the shfiter but you may be able to cut out the floor and weld in a hump like they did in the older cars. Their floors were extended for the shift brackets. If you're going 4x4 anyway do a 3" body lift. That should solve alot of the space issues with the tunnel.