So I have been told that before I start butting any big amount of money in to my engine, to up the power. I should check the compression. And the question is, what is a good compression for my 1971 bone stock 455 Electra 225, with 64,000 miles? The dudes I have spoken to have said from 160psi to 180psi, all with the same no more than 10% varince across the bunch. But I wanted to here it from some Buick Dudes, to be safe.

In my experience up to 25% variance is acceptable in most used engines. If your compression is less than 140psi then you should be concerned. Older engines were built with lower tolerances than today's engines, and 65000 miles + 33 years doesn't help.
If you don't know how to check compression properly, here's how:
Disconnect the wire from the ignition coil to the distributor, then block the throttle wide open. Attach the compression guage to each cylinder and turn the engine over 3-5 times (you'll be able to tell by the sound).
Record the reading on the guage once you've stopped cranking the engine.

Good luck!