My 67 Coronet convertible ws this way. Sat long time and the friction disc came loose from the plates. Would drive and shift thru all forward gears, but no park, neutral or reverse.
As far as the add, the guy doesn't know the 360 is a small block? Well there are so e people that get told something and believe it. If interested might be worth a look if the price is right. But he might have seen too many BJ reruns too.
