First start question reguarding exhaust manifolds

Had my brother (a welding student) weld some some flanges on a pair of glass packs (temporarily) so I could muffle the fenderwell headers on my '65 four door Valiant bracket racer during start-up and driving to the muffler shop (30 mile trip).

Without tail pipes or muffler hangers, Dad helped me support the glass packs on each side of the vehicle by wrapping chains thru the two rear door handles. Kind of a hillbilly way to do things (lived on a cattle ranch at the time). Salinas cops stopped me on the first day, and chewed my *** out, but let me go.