I just had my engine swap, I changed the pistons, valves, valve springs and retainers all type Rs. I didn't change the cams yet and no fuel regulator, would that be okay for a while because I'm going to get a new set of cam gears and fuel reg when I'm done breaking in the engine.

 

Thats fine. The drawback will be that your car will most likely run a little crappy until you get all those parts in and tuned.