I have the peavey 6506+ 1x12 combo, and a peavey XXL 4x12 slant cab.

The cabinet is 300W and 16 ohms by default.

My combo is 60W and I'm not sure what the impedance on it is...I can't seem to find that anywhere...
The amp can switch between 16, 8, and 4 ohms.

The combo has two parallel speaker outs on the back. One of which usually connects the stock speaker to the amp. I've been running the combo into the 4x12 at 16ohms, and unplugging the 1x12.

Can I safely run the 1x12 speaker, and 4x12 cab at the same time, and if so what do I need to set the impedance on the amp to?

I wasn't sure what adding that 12" to the load would do as far as impedance is concerned.
"The mind is everything. What you think, you become."
You can open the combo up and check out the speaker yourself. If it is 16 Ohms, plug both in and set to 8 Ohms.
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The speaker looks like it's 16 Ohms.
Ah duh, two 16 Ohms make for an 8 Ohm load.

"The mind is everything. What you think, you become."
the manual also says it is a 16 ohm speaker.
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well played with the thread title
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