The custom car registration is the way to go, only issue is finding an ASE Master tech inspection. My Backdraft wound up being registered as a 65 Ford, just depends on the DPS office, kind of a crap shoot. The custom car route is much better, you only need the ASE inspection once. All of this info is available as a pdf from the Texas DPS.
This is the primary reason I chose a Texas builder for my new Cobra (UCC), they do all the registration and title work. Unlike BDR which was a pain in the rear end.
http://content.govdelivery.com/attac...e%2BManual.pdf