When I turn my steering wheel all the way right or left it makes a repeated chirp noise. It chirps every now and again when I move the steering wheel when the car is not moving. What is this?

It is common for the unit to chirp or sing on full lock.

How do I make it stop?
It didn't do this before...
Seems like it started after I put in the 383 & march kit.
What is full lock?

Full lock is the last little bit of turn either way on the steering wheel
I assume u have power steering??

I do. However, it doesn't just chirp on full lock. It chirps when I am turning the wheel at low speed or at a stop. The wheel will be difficult to turn, and when turning it over it will chirp about once every five seconds. Then at full lock it chirps repeatedly every half second.
It didn't used to do this when I had the 327 without the march kit.
I doubt it is the belt.

The belt is probably slipping, either on the crank or pump pulley. Have someone turn the wheel while you watch the belt.

As David said , belt slippimg, replace it or tighren it.