1988 olds ceari cruser NO START

I think you are right to think its the timing chain. The valves may have been damage but you won't know untill you fix the chain. Check with your local dealer and ask if that motor is a interference motor, which means the valves can strike the pistions if the timing is not correct. However if the chain did not let go while you were driving then there is a chance (even on interference motors) you may not have damaged the valves. Good luck Backyardmechanic :(