[Jeb]

The stroked 390 can be a powerful engine.
Your plan to use hydraulic roller lifters however may need some rethinking. Their use in the mix will limit your top RPM's to 5500 max, even with Ti valves and retainers you won't be able to rev much higher than that and there are no rev kits for the FE.

The Cobra needs revs. You don't say what trans type you're thinking of. If it's an auto and you're looking for street use out of this car only, then the Hydraulic rollers would be fine. If you're going racing, sometimes, I'd look at some other form of lifter.