Stock Magnum EFI with a cam upgrade.

I don't think that ODB1 system will play nice with that camshaft. They don't like a lot of valve overlap. It may work because the OBD 1 adaptive learning is more than capable of adding enough fuel via the stock injectors but the intake manifold will be done by 4000rpm's anyway. On top of that you can't flash that controller. So I wouldn't try it. Those early ECM systems like high and constant vacuum at the MAP sensor.