Dumb Question. Anyone have any idea what kind of issue would make the power steering work fine when cold, but once the car heats up it whines like you wouldn't believe and bogs down?

If it matters, 89 Daytona Shelby, 2.5; No AC; Oversize alternator

I've had the whole system out down to the Rack, it's all new... don't remember having this issue, but the car did sit for almost 2 years, so i might be glamorizing it.