[dsraven]

TF frames are the same between chevy and gmc. unless someone else has some input. you can get that info from the assembly manual (recommended purchase if you haven't already) or online at the old car manuals project. check on google for frame dimensions, there have been a couple on there.

what is the plan for steering, diff etc? will you be lowering it and installing power steering, disc brakes or a clip from another vehicle? possibly a mustangii front end? different rear axle for a better gear ratio? leaving it all stock? I would recommend at least a dual system master cylinder if you are leaving it stock. the old one is only a single system so if you blow a hose or get a leak somewhere you lose ALL the brakes, not just fronts or rears.