I just installed a new power steering pump on my 65 chevelle. Belt tension is perfect as well as fluid level. My problem is whenever I turn the wheel all the way to one side and hold it there, I hear a very loud screeching (from the pump). From my research I assuming that the pump has some air in it. What is the proper method for removing air in the system. Thanks in advance!

That screaching you are hearing is the pump going into pressure relief. I hope that you haven't held it at full lock for more than 5 seconds each time. Holding it at full lock with the engine running can quickly ruin a power steering pump.

Air in the system can also result in a noisy power steering pump. If you have air in the system the fluid will look milky from the fluid getting whipped to a froth and millions of tiny air bubbles in the oil. The pump will usually make noise just as soon as you start to steer. You won't have to be at full lock to hear the pump noise.

After you have changed a steering component, it is best to jack up the front end of the car, refill the system, and rotate the steering wheel full lock to full lock a couple dozen times WITH THE ENGINE OFF. Refill if the fluid level drops. Then drop the car down and start the engine. Go for a short 10 mile drive. You should be good to go.

I also recommend that you fill the system with genuine GM power steering fluid, (available through GM dealers.) It is the only fluid that is specifically formulated to operate with the GM (Saginaw) power steering pump.
Jim

I hear a very loud screeching (from the pump).
First Guess: If it's LOUD and SCREECHING, it's BELT SLIPPAGE. If it's a noticable hum or whine, it's the pressure relief valve in the pump, and it's entirely normal.

Verify the tension, and look for a damaged/worn/glazed belt, damaged pulley/groove, or misalignment of the pulleys.

Might paint a stripe on the pulley from the center toward the edge, and have a friend crank the steering wheel while you watch the pulley. If the belt slips, you should see the speed variation of the pulley by watching for irregular movement of the stripe.