does this vehicle use a belt or chain???
if it's a chain does it require chainging like a belt??
if it's a belt how much miles before you change??

 

Chain; no preventive maintenance required.

 

There is a way to check the wear on the chain and gears without removing the cover. Hook up a timing light and watch the timing mark as you rev up and down the rpm's. This will throw the slack in the chain from one side to the other. I can't exactly remember the spec but I would say over 1 inch of the mark distance is worn chain and/or gears. Make sure you rev it up beyond where the advances start in the distributor, if it has them. You could remove and plug the vacuum advance but the mechanical one is actually the weights and springs on top the distributor. Just rev it up slowly untill you notice no more advance, then rev it up 1,000 more rpm and back down 1,000 rpm back and forth and watch the timing mark. Chains are on the last process of oiling and only get drips or splashes from what I remember.

 

95% of lose or worn chains will hit the chain cover and driveability problems.
I don't think the OP has a chain problem, just asking if it ever needed to be changed.