As long as you expect that nothing is going to work between the Magnum and the LA, you should be good. You might want to take a good look at a factory V8 Dakota before you jump in though, oil pan clearance and exhaust will probably be an issue, the Dakota places the motor in different locations that the LA motors were located, so LA parts that clear stuff might be a challenge.

If you're like me and you have a torch and a welder and know how to use both, your swap shouldn't be too hard. Gene