First of all, get your insurance issued as a 1965/66 Cobra, whatever you choose. If you need a solid insurer who can handle this, call Robbin and Norma Terry and
Midwest Classics. Once you have the insurance card, take it and the car to a local Kwik Lube or similar
oil change shop. Leave the title at home. The Kwik Lube will initiate a record in the TX DMV computer for the fist time as a 1965 or 1966 Cobra because that's what your insurance says. They'll inspect it for safety only (no emissions) and give you a receipt, $14.50. Take that, your insurance card, your Michigan title and your check book and go to the local tax assessor office. They will do the rest and you will walk out titled and tagged. FYI, this is the LEGITIMATE way to do this.
Jim
P.S. Scrape the Michigan stickers off of the windshield beforehand.