Whenever I read datasheets regarding shift registers, they always stae things like "the register can handle 50MHz MAX. I was more hoping to run it off of, maybe, 3 or 4 Hz, in hopes of using it to delay a signal (high).

But my point is this; can I run a shift register off of such a low frequency? I've already got my 555 chip pulsing at a 3.5 Hz rate. Are there some registers that can and some that can't? This is where google can't help me

Thank you

 

I would take a guess and say you could operate the sheift register as low as you wanted pretty much. Give it a try, shift registers don't cost much.

If you have access to a signal generator test it out changing in the input frequency and see what reults you get. That's the fun of electronics, you get to play and test things . And if you're lucky things blow up once in a while. hehe

 

The clock frequency can be very low, but the edge rates must remain relatively fast.
Run the 555 output through one or two Schmitt trigger inverters (depending on polarity or timing), such as a 74HCT14 or similar device.