Few questions on having and engine built.

Just handing over a pile of parts and saying 'build it' is a poor formula. First think each out each step like you were doing it. Then:

1. Write down a list of exactly what you want done and spend some time up front going over each line item. Don't assume that they will know all the small things that you would want done. And discuss clearances and technical details.
2. Ask how they do the important thing. Each shop will have their own preferences and procedures. You might pick up on something that they would do that you question or don't like, or find out things that you did not know.
3. Ask if you can be called to look at the work at stages. Things like cam bearing installation and how well the holes line up can be vexing.

Engine builders are typically pretty sharp cookies, so if you run into one who can't or won't explain things then move on, IMHO. Some are easy to talk to and some are not. I'd be looking for the ones who will take time to answer reasonable questions.

Do you have local hot rod friends who can make recommendations?