It seems unlikely it needs adjustment. If it's slack it will show up as
slop or play between crankshaft and distributor rotation. Check by
removing the distributor cap and rotating the dynamic balancer back and
forth and noting how many degrees you can move it before the distributor
moves. Just for the hell of it, seeing as how the rubber is as old as
the car, have you checked the rubber hose that connects  the mass air
flow sensor to the intake manifold. The convolutions may have cracks.

That's the LAST thing to look at for your complaint. Highly unlikely
"timing" is the problem, it just the ONLY thing possible that costs nothing
other than time to fix. Maybe it's a fuse? That's the next cheapest thing
to check..