[87chevy.com]

I built my entire front end accessory bracket system with a strait edge black and decker level and harbor frieght dial caliper and no squeaks at all.



From my experience in getting alignment down, put a long stait level against the crank pullley and attach it with a quick squeeze clamp. This allows you to use your hands. Crank pulley won't spin...
Then it's the dial caliper to the rescue.

No need to guess... measure from strait edge to the first groove in the balancer..
Then go and measure the the distance from the same edge to the compressor groove that your using/fits best and shim accordingly.

Something you could check... if you rev the engine and the brackets flex.. as in you can see it flex, that's an issue. Not likely, but something you could visually see for free.