I just bought it, and I can't locate speakers in it. Can someone tell me where they are SUPPOSED to be located?

Thanks!

 

top of dash at the ends, or maybe just one speaker in center of dash. some of these trucks had them in the door from factory.

 

According to Crutchfield:

1986 Chevrolet C Series Pickup Factory Stereo Installed
Factory replacement info:

In-dash stereo: 12" depth; Size code E,S,U

Front speakers
Dash: 3-1/2" factory speaker note
Kick Panel: 6-1/2" factory speaker note
Front Door: 6x9" Important requirements

Far rear speakers
Behind Seat: 4x10"

E: "Euro-DIN" stereos attach from the front through the 2" tall rectangular hole in the dash, sliding into a metal sleeve that attaches to the front of the dash.
U: "Shaft-style" receivers have two ***** on either side of the tuner/tape deck. They fit the 3-hole dash opening in many older vehicles.
S: Similar to "U" chassis, but with a taller nosepiece or offset shafts. They fit the 3-hole dash opening in many older vehicles.