Power Steering Noise

Pic will help. I dont know what set up you have. P/S belt on my 67 is crank and p/s only. It is a wider section belt than the water pump/alternator belt. Wrong/belt will run in the bottom of the p/s pulley instead of driving its sides. Advance auto clerk did try to sell me a wrong belt once. I had to edumcate him. More to it than belt length alone.
You might get to squealing and toss a cup of water on the belts. If the squeal stops for a second or changes at all, there is you squeal. In the textile mill I learned to use sidewalk chalk to dry wet belts, diagnose contact, etc... but this practice is dangerous.