Three years ago, I conducted a survey of actual auction results for 1966 GT350s for the previous five years. After discarding the extremely low figures for rust buckets or cars with incorrect equipment as well as those selling on the extreme high end (1966 GT350 convertible, celebrity cars, charity fund raisers, etc.), I found that Hagerty's of $175,000 and up for correct condition 1 and 2 cars was more accurate than most other sources. Also, a friend purchased a 4-speed numbers matching condition car for $175,000 the year before.
If you have one of these cars and purchase and agreed value policy from Hagerty, that is the price they will pay in the event of loss with no deductible.