I have a 1970 Ambassador what is it worth?

check ebay using the bidders you can get a general idea of what people with pay.

Checking ebay is good, but it'll vary widely with condition, bodystyle and equipment. 2 doors are worth more than wagons, and wagons are worth more than 4 door sedans; the more equipment the better, the bigger the engine the better- and, as with most AMC products, the biggest selling point is the condition of the interior- if it's good or excellent, people will overlook mechanical or body issues if not too severe (Interior parts for AMCs are VERY difficult to get).