#1
Can you plug a peavey vypyr 60 into a cab?

and would it work if you plugged it through the headphone slot of the amp?
Gear

Guitars
Ibanez ART 300
Squier Strat
Godin 12 string Antique cedarburst
Ibanez RGD 320

Amps
Peavey Vypyr Tube 60W
Peavey Solo 15 W
Fender 10 W

Effects
Dunlop GCB - 95 Crybaby wah
Boss DD-7 Digital Delay
Boss MT-2 Distortion
#2
If my vision works properly, It looks like theres a Speaker Out.
Which one do you have? The black or Gold one? I saw 2 kinds.

The speakers in a cab aren't powered on their own, so, no. No headphone out to a cab.

With modifications, you could mod it to have a speaker out if there already isn't, but it is very difficult, and I do not reccomend it.
..I was watching my death.