Thanks for all the suggestions.
I talked to the people at Am. Autowire and I figured out what I did.
The harness had a provision for a neutral safety switch, which I am not using. If you aren't using it the two wires must be connected together. I knew this, but totally forgot about them.
I connected them up and it turned over.
In the process I also found out that apparently I don't have an internally regulated alternator, mine is external, so I had to replace that too.

Problem solved.