340 gone! Performance shop shut down! Help!

I'd stop in to some of the other local machine shops in your area & ask them if they know anything at all about their whereabouts. Explain your situation to them & that you're not looking to involve them at all just trying to find out about your engine & the guys who have it. The automotive community is a small world & everybody knows their competitors & usually the dirt on them. Espescially machine shops. Maybe you might run into someone who worked there or knows someone or where they can be contacted.
This really sucks! Thanks for your service to our great nation!