[Sirrotica]

If it only jumped one tooth it will run terrible because the cam is retarded. If it jumps more than one tooth it most likely will not start or run at all.

No sure way of telling other than remove the timing cover and checking the marks, that I'm aware of. You could remove the fuel pump to check and see how much slop there is in the chain. A Pontiac would have to have a lot of wear to jump a tooth with steel gears. If you happened to still have an engine with a nylon cam gear, it could jump easier if the teeth were falling of the sprocket. Pretty rare 50 years after they quit using nylon gears for one to survive though.

I replaced a nylon timing set, lying on my back in a driveway once. I was hurrying, and I accidentally got it off one tooth off, it barely ran. As many Pontiacs as I've worked on over the past 50 years, I can't remember any that just jumped over one tooth, the timing chain would have to be severely stretched for that to happen. Very uncommon in my experiences.

Now if you are talking Pontiacs with nylon cam gears (65-71, before 65 they used steel gears, and after 71 they reverted to steel cam gears) they jump when the teeth strip off, but they don't continue to run. You're dead in the water when this happens because the cam gear strips all the teeth off and usually doesn't turn at all. I've seen many many Pontiacs strip nylon cam gears, they stop running when it happens.