My '03 doesn't have much behind the headliner and the '88 didn't so I am guessing NOT! But there is still a lot of support up there.
I mounted a small CB, a Uniden 520 with pwr mic on a small overhead console I built and mounted to the Headliner. I thought it would bounce and pull the headline down but in five years of use it never did.
How big is the CB you will be using, if small then you might use a 1/8 or 1/4 x 1 or 2 inch aluminum strip on the top side of the head liner and bolt through it to mount the CB Brkt.
Make the strip longer than the CB Mounting brkt so it will spread out load.
Run both the Power (red +) and Ground (blk -) wires back to the battery using a fuse on at least the power wire and as close to the battery as reasonable. Run an additional wire from the chassis of the CB (one of the rear cover mounting screws) to a good grounding point maybe to a ground point close to the battery or on the engine.
Just thinking...
Luck,