I may need to adjust the parking brakes on my 78 cutlass salon.

can the right,and left cables be adjusted seperately? if so,how?

Not in your case.
Cable actuated brakes will always have an equalizer, of some sort, to compensate for the unequal wear on the friction media, so there can only be one (shown below) adjustment .



When the E brake is seldom used, it can become inoperative because of dirt, rust, etc. A faulty brake, on one side, can show the same symptoms.

Norm

thanks for the diagram:)

I noticed that the spring on the end of the LH cable inside the drum was more compressed
than the one on the end of the RH cable in the drum . I'll adjust things up and see what I get. the linings on the rear axle I swapped in have just over 600 miles on them.
the linings on the original rear were down to bare steel.
maybe I need to adjust to compensate for the different linings.

I'll adjust them once I put the wheels back on. thanks again!!

Let us know how it goes.

Norm