I did a swap in my 70 Cuda back shortly after MSD came out with the Hemi 6. I am running a Mopar carb manifold with an Edelbrock 750 and the Hemi 6 controller. I like it and have never had any issues with it.
I've never messed with the factory timing curve or anything else. I would be interested in hearing more about what you turned off and how you benefited from changing your timing curve.