1975 Pontiac Trans Am 455

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1975 Pontiac Trans Am 455

In 1974 the gas crunch was in full swing and peak of the muscle car era ended. Then Pontiac announced there would be a 1975 Trans Am with a 455 HO package. It included the 455 HO shaker hood, a 4-speed floor mounted manual trans with a 3.23 performance axle ratio, semi-metallic front disc brakes, and a specifically tuned exhaust system with twin exhaust splitters. Here's another full build Trans AM we're doing and in the process becoming Trans Am experts. Luke’s 1975 came to us as a nice, complete painted, running and driving car. Upon disassembly we found a bit of covered up rust and low quality repairs. Like most cars its age it had already seen some level of restoration but Luke is having us take it to the next level with a ground up, bare metal/new metal, Pro Touring custom build. Starting with a Schwartz G-Machine performance chassis and GM LT4 Supercharged motor with a Whipple supercharger in place of the stock unit - this bird is gonna fly!

Frame and Suspension

  • Schwartz Performance bolt-in G-Machine Chassis
  • Ridetech single-adjustable coilovers
  • Power steering rack
  • Baer 14" 6-piston Pro Plus brake system w/rear floater kit
  • HD splined sway bars front & rear


  • Chevrolet Performance Wet Sump LT4 crate engine
  • Upgraded camshaft, valvetrain & pulleys, Innovators West crank pulley
  • Whipple 2.9L supercharger
  • Chevrolet Performance LT4 controller kit w/harness & ECU
  • Drive Junky LT4 serpentine drive system
  • Methanol injection system
  • Estimated horsepower: 900hp at the crank


  • Chevrolet Performance 8L90e 8-speed automatic transmission
  • Chevrolet Performance Supermatic trans controller
  • Custom steel driveshaft
  • Moser full-floating 9" housing & 35 spline axles
  • Currie 9” iron third member, 35 spline axles, TrueTrac differential, 3.25 gear

Wheels & Tires

  • Forgeline TA3 wheels, 19x9 front, 19x12 rear
  • Michelin Pilot Super Sport tires, 265/35/19 front, 345/30/19 rear

Paint & Body

  • Custom fabricated steel fender flares front & rear
  • Filled marker lights front & rear
  • Fiberglass bumpers
  • Custom hood bird by StickerDude
  • Paint color - pearl white


  • Recaro Sport seats
  • SpeedHut custom gauges
  • Twist Machine paddle shifters
  • Billet Specialties steering wheel
  • Flaming River tilt steering column
  • Vintage Air Gen IV A/C system
  • Customized DSE 4-point roll bar
  • Lokar sport shifter
  • Upholstery TBD 

Other Features

  • BeCool 1000hp-rated aluminum radiator module w/electric fans
  • Stainless EFI fuel tank with CTS-V pump & Vaporworx pickups
  • American Autowire Highway 22 wiring harness
  • Optima YellowTop battery


Disassembly gallery

After chemical stripping.

Chassis fabrication and installation

Sheet metal fabrication

Pre-assembly & mockup 

Interior related

Bodywork & paint

Final Assembly