Frequently Asked Questions
at Texas Trans Ams

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  1. What does the average restoration involve?

  2. Would it be cheaper to have my car restored or buy one already completed?

  3. How long does a full restoration take?

  4. What does Texas Trans Am Service and Restoration do?

  5. Why do you focus on Second-Gen Firebird?

  6. How long have you been in the business of restoring muscle cars?

  7. Do you buy project cars?

  8. What is your background in auto repair and restoration?

  9. How can I tell a Black Special Edition Trans Am (1977 - 1981) from a regular Black T/A?

  10. What does the WS6 Suspension Package option include on the 1978 through 1981 T/A?

  11. What does the badge on my dash mean by Radial Tuned Suspension (RTS)

  12. Which cylinder head was offered on the 220 hp 400 in 1978 and '79?

  13. How does cylinder over bore affect displacement

  14. How does cylinder over bore affect the Rated Compression Ratio?

  15. Can I use engine parts from a Pontiac 400 C.I.D on a 403?

  16. What's the difference between a concourse restoration and a Texas Trans Am restoration?

  17. If you had to compare the Texas T/A Mufflers to Fl*wmasters in sound & sound level, which kind do they sound like?

  18. Are you open on Sunday?

Also please review David's presentation to DAPA for more
questions and answers


Q1: What does the average restoration include?

A: Texas Trans Am does not perform an "average" restoration, however full "frame-off" restoration envolves a lot of labor. This includes disassembly of all interior, suspension and body parts, with appropriate cleaning, rust neutralization, coating or replacement. Rusted or damaged body panels are replaced or repaired. All gaskets, bushings and upholstery is replaced. The repaired body is coated in primer and after curing for 30 days is painted with Urethane and color sanded by hand. We consider the restoration results to be "Street Restorations" or "Car Show Restorations" they are not intended to be "Concourse Trailer Queens."

Q2: Would it be cheaper to have my car restored or buy one already completed?

A: Buying a car already restored will almost certainly cost thousands less and get you cruising the street sooner. Remember, when you buy a car already restored, you are buying someone else’s car, built to someone else’s specifications, with the parts they selected and their level of expertise and detail. A great percentage of Texas Trans Ams’ Service work is done to improve or repair someone else’s interpretation of a restoration.  Many customers buy what they are told is a fully restored car only later to find that the previous work was inferior or not done at all. If Texas Trans Ams restores your car it will be done to your specifications as if you had ordered the car new.

Q3: How long does a full restoration take?

A: A full "frame-off" restoration at Texas Trans Ams takes from 12 to 18 months. All parts are removed and each individual piece is cleaned, stripped or sandblasted. Rust is neutralized and parts are coated or primed. Many steps in the process are scheduled to coincide with other restorations. Primed body panels are allowed to cure for 30 days. Finally all parts are assembled and finished by hand. Our work is not collision repair or just a paint job it is full restoration.

Q4: What does Texas Trans Am Service and Restoration do?

A: The majority of the service and restoration work done at Texas Trans Ams involves 1970 through 1981 (Second Generation) Pontiac Firebirds, including Esprit, Formula and Trans Am.  Restoration and service is welcomed on 67 through 69 firebird, but parts are generally not stocked and prices tend to be higher. A few "strays" wander through the shop as well including 1964 through 1973 Mustangs and Cougars and Second-Generation Camaros. We cater to the late 60s through late 70s two door American performance car enthusiast.

Q5: Why do you focus on Second-Gen Firebird?

A: To fill a gap in the Pontiac muscle car restoration market. GTOs and First-Gen Firebirds have their share of restoration experts, and we love those cars too. Several businesses have opened and closed in the past 10 years that focused on restoration services for the Second-Gen Firebird, but by building a business slowly and controlling quality carefully Texas Trans Ams has purchased most of their inventory. The prices for a project starter Second-Gen. Firebird are still within reason for the average sporty car enthusiast. Even if you spend 10 or 15 thousand dollars to complete your project, you can’t buy anything like it new for less than 30 thousand. And over time they will appreciate in value, as they become more rare.

Q6: How long have you been in the business of restoring muscle cars?

A: Professionally David has been restoring and servicing Firebirds since 1991, but he still has the 1967 Mustang he rebuilt in 1977.

Q7: Do you buy project cars?

A: If you are looking to get rid of a late 60’s through late 70’s two door American muscle car or project parts, send me an e-mail. We get calls and messages from people looking all the time.

Q8: What is your background in auto repair and restoration?

A: David Mars, the owner and operator of Texas Trans Am Service and Restorations, has been involved in model cars for years, fabricating and painting miniature parts, and substituting parts from one model to another.  Some of David's models have been featured in model car magazines and even toured the country with a model car exhibit.  

David has been a professional painter since 1982.  He learned how to shoot Urethane painting high-dollar tractor-trailer rigs for both the Douglas Company and Bell Petroleum for over 4 years.  David has been focusing on the Second-Gen. Firebird since 1991.  Over the years David has developed an extensive network of experts to help with auto restoration components, with final assembly completed at the Texas Trans Am Service and Restoration shop.  David has been a guest speaker on Second-Generation Firebird restoration at DAPA, retained for professional appraisal of domestic sports coupes in a legal proceeding, and is often consulted for authentication of originality of collectible Second-Gen. Firebirds. One customer’s car was featured in an episode of Walker Texas Ranger.  Texas Trans Ams serves domestic customers from California to New York and Alaska to Georgia and internationally from Canada and the Cayman Islands.

Q9: How can I tell a Black Special Edition Trans Am (1977 - 1981) from a regular Black T/A?

A: If the car is SE and has not been tampered with it should feature a gold bird in the horn button, gold tinted spokes in the steering wheel, and a gold bird in the shifter knob if automatic.  The SE came with a gold tinted dash bezel with a black tinted bead around the outside as opposed to silver on silver.  Most dash bezels with gold coloring have faded over time to be indistinguishable from silver at a glance, to verify the original color, pop out one of the plastic instrument rings to see if it is still gold tinted under the protection of the ring.  If the interior is still intact the build sheet should be between the foam and springs of the back seat and one of the last lines should read Y82 or Y84 for T-Top.   The 1979 through 1981 SE had a gold Pontiac arrowhead emblem on the nose. 

Q10: What does the WS6 Suspension Package option include on the 1978 through 1981 T/A?

A: With the reduction in horse power due to emission and gas mileage regulations performance enhancements were made in traction, and handling through the combination of components offered in the WS6 option.  This package helped the nose heavy sport coupe to have a more neutral feel under real world driving conditions and handle as well or better than any other American car of it's time.

Year and Model Lateral skidpad acceleration  Source
1969 Camaro .66 G's Suspension Test Report in Herb Adams' VSE Catalog
1973 Corvette .79 G's Suspension Test Report in Herb Adams' VSE Catalog
1978 Camaro .71 G's Hot Rod Magazine, June 1981
1980 Trans Am WS6 .81 G's Car & Driver, September 1979

The WS6 package was first available in 1978.  It included:

  • 15" X 8.0" aluminum snowflake wheels shod with 225/70R-15 Goodyear's
  • 1.25" front anti-roll bar with hard plastic bushings
  • .75" rear anti-roll bar
  • Stiffer rear springs
  • Stiffer rear shackle bushings
  • Firmer shock valves
  • Closer ratio steering
  • Lower control arm supports

The WS6 package was upgraded in 1979 to include:

  • 4 wheel disk brakes with 11.1" rotors
  • 14:1 constant ratio steering box in place of the 15:1-13:1 variable ratio unit
The lower control arm support is not really on the control arm. It bolts to the back side of the lower control arm housing and on the curved part of the sub-frame.  This support is small and relatively thin.  It is about the size and length of a big pencil connecting frame to frame for the inside of the curve.

Q11:  What does the badge on my dash mean by Radial Tuned Suspension (RTS)

A:  In the 1960's and early '70's the performance tires offered from the factory was the F60-15 bias ply tires.  However for daily driving comfort bias ply tires left a lot to be desired.  Pontiac introduced the "Radial Tuned Suspension" to the automotive world to improve the ride quality and performance offered by the new GR70-15 radial tires.

RTS (Radial Tuned Suspension) in 1974 included the following:

  • GR-70-15 radial tires
  • Front anti-roll bar diameter shrank on the Trans Am from 1.25" and grew on the base model from 1" both to 1.125".
  • Rear anti-roll bar diameter also shrank on the T/A from .875" and grew on the base model from .625" to .75".
  • Stiffer springs - 330in/lb. fronts and 125in/lb. rears up from 300/100
  • Heavy-duty, re-valved shocks
  • Altered bushing durometers

Q12:  Which cylinder head was offered on the 220 hp 400 in 1978 and '79?

A:  Two versions of the 1975 - 1977 "6X" cylinder head were produced.   The head designed for the 400 cid has a chamber volume of 98.09 CC's.  The head designed for the 350 cid has only a 91.11 CC chamber.  The difference is in the size of the chamber scallop on the spark plug side.  The big chamber head matches the 4.12' bore size while the smaller chamber matches the 3.88" bore size.  The heads can be identified without removing from the car by a number stamped into a flat machined pad just below the valve cover surface, above the temperature gauge fitting.  The small chamber heads are stamped with a "4" and the large chamber heads are stamped with an "8".  However, when installed in a car the number faces the ground so a mirror and a flashlight comes in handy.  To increase compression ratio, and in turn horse power, the factory substituted the small chamber 6X-4 heads on the performance 400 engines in 1978 and 1979. 

Among Pontiac heads designed for un-leaded gas, the 6X is considered the best flowing medium compression head for street performance on "pump" gas.  Since the lead in gasoline that helped to lubricate moving parts was removed, the 6X features hardened valve seats in it's 2.11" intake and 1.66" exhaust valve.  The 6X head has an exhaust to intake ratio of 78.7%, these numbers approximate the classic theoretical ratio of 85% (the RAM Air and SD heads from 1967 through 1974 had a ratio of 83.9%.

Q13: How does over bore affect displacement

Common Pontiac Displacements and Overbore Displacements. 400

inches metric
bore 4.1212"
stroke 3.75"
overbore 0 0
displacement/cylinder 50.023 ci's 819.72 cc's
displacement 400.18 cid 6.557 liters
new bore size N/A

400 bored .030" over

inches metric
bore 4.1212"
stroke 3.75"
overbore 0.030
displacement/cylinder 50.75 ci's 824.43 cc's
displacement 406.03 cid 6.595 liters
new bore size 4.1512"

400 bored .040" over

inches metric
bore 4.1212"
stroke 3.75"
overbore 0.040
displacement/cylinder 51.00 ci 835.71 cc's
displacement 407.99 cid 6.595 liters
new bore size 4.1612" 10.57 cm

400 bored .060" over

inches metric
bore 4.1212"
stroke 3.75
overbore 0.060
displacement/cylinder 51.49 ci 829.15 cc's
displacement 411.92 cid 6.633 liters
new bore size 4.1812"

Overbore Displacements Calculation

(Webmaster's attempt to explain the calculation)

400 CID

Cylinder Bore Diameter   4.1212"
Cylinder Bore Radius Diameter / 2 4.1212 / 2 =  2.0606"
Cylinder Head Area Pi * Radius * Radius 3.14159 * 2.0606 * 2.0606 = 13.3394 sq inches
Stroke 3.75"
Displacement/ Cylinder Area * Stroke 13.3394 * 3.75 = 50.023 cid
Engine Displacement Disp/ Cyl * # of Cyl 50.023 * 8 = 400.18
  1. To arrive at the Cylinder Bore Radius, divide the Diameter by 2.
  2. To arrive at Cylinder Head surface Area, multiply the value of Pi (3.14159) by the radius squared (Radius times Radius).
  3. Area of Cylinder Head surface multiplied by stroke equals Cylinder Displacement.
  4. Cylinder Displacement multiplied by number of Cylinders equals total Engine Displacement.

Q14: How does over bore affect the Rated Compression Ratio?

Cylinder Displacement plus Head volume divided by Head volume.

This is based on a "mythical" engine with flat top pistons, with a 0 deck height including the head gasket, but the percentage changes should give an indication of performance improvement.

cylinder bore volume head volume total volume head volume rated compression ratio
819.72cc's (400 cid) + 98.6cc's (6X-8) = 917.78 / 98.6cc's0 = 9.36:1
819.72cc's (400 cid) + 91.11cc's (6X-4) = 910.83 / 91.11cc's = 9.99:1
835.71cc's (400 .04" over) + 91.11cc's (6x-4) = 926.82 / 91.11cc's = 10.17:1


Q15: Can I use engine parts from a Pontiac 400 C.I.D on a 403?

A:  The 403 and the 400 are COMPLETELY different motors.
The 403 is a small block built from 1977-79 based on the Oldsmobile 350 engine. The stock 403 Olds, or 6.6 Litre, is rated at 185 hp @ 3600 RPM, 320 ft/lbs torque @ 2200 RPM, 4.351 inch bore by 3.385 inch stroke, 8.0:1 compression ratio.
The 400 is a Pontiac engine based on the 389/421 engine from the early '60s.  The T/A 6.6 Pontiac motor produced 220 hp @ 4000 rpm and 325 ft/lbs torque @ 2400 rpm, 4.12 inch bore by 3.75 inch stroke.

Nothing is interchangeable.  Starting at the top even the carburetors have different part numbers and base plates. At the bottom the motor mounts are the same and mount to the frame rail cross member in the same place, but the motor brackets are different. On the sides the exhaust manifolds are not interchangeable, even the lead pipes line up differently. At the front the radiators are the same, but the fan shroud and radiator hose are different. At the back of the motor the good news is that the bolt pattern is the same for the transmission bell housing, a Pontiac will mate up to an Oldsmobile or Buick transmission and vise versa, but the Chevy transmission is different.  However the complete 400 engine will fit in place of the 403.
Editor's note David says the engine can be removed from a Trans Am without removing the hood.  The hard part is squeezing it out through the hole in the center of the hood.

Q16: What's the difference between a concourse restoration and a Texas Trans Am restoration.

A:  A Concours restoration is a rolling time capsule, wonderful to see at the shows and great fun to drive if you consider moving a car from storage to the transport trailer a "drive". Concours level restoration entails returning the car to exactly the way that it came from the factory, not just the way it left the dealership. This includes not just the factory color but quality of paint job. Since the factory painted and assembled hundreds of cars each day the assembly line fit and finish would show orange peel in the paint and body panel gap differences may vary from 1/8 to 5/8 comparing one side of the car to the other. They duplicate all the factory plating on nuts and bolts, brake booster, hood hinges. Inspection marks such as paint daubs and part number tags are also reapplied.

A Texas Trans Am restoration is focused primarily on the quality of the fit and finish, secondarily on the drivability and serviceability. Theses cars are great to look at too, but we prefer to drive them.
(Use your monster truck announcer voice here.)
(You can use your indoor voice now.)
It's David's vision of how the car could have been delivered from the factory, if the factory built each car one at a time, each with it's own quality control engineer following the progress throughout the assembly process. In a way these restorations fall under a category of "Over-Restored" in regards to the fit and finish. The Texas Trans Am cars also benefit from modern technology but not to the extent that it detracts from the appearance of the era. For example acrylic urethane paint is used for non-metallic rather than water based enamel for it's durability. Each step in the primer and paint process is block sanded and the acrylic urethane paint wet sanded, then buffed to a mirror finish. The massive doors are floated and block sanded to remove the ripples in the edges from the factory. The door hinges are rebuilt and all attached sheet metal and urethane is re-hung and aligned to David's exacting standards. Poly-graphite bushings are used on the upper and lower control arms rather than the original rubber to improve the handling and stability. Unpainted portions of alloy wheels are clear coated to prevent pitting and staining from oxidizing brake dust. Sub-frame and suspension components are coated with a modern rust preventative designed for protection from water, chemicals, salt, and mineral oils far superior to the wax coating from the factory. Want a hotter street cam, aluminum intake and heads, rear disk brakes on a pre '78, modern stereo equipment, Fisher t-top roof on a non t-top car, chrome valve covers on a non W-72, true dual exhaust with Texas TA Mufflers, Hi Performance Ram Air Exhaust manifolds that look stock, larger than stock wheels and tires, gas filled shocks rather than hydraulic, or DOT5 silicone brake fluid in a completely new braking system that's OK too. By the way, don't try the previously mentioned "spirited" lunch run in a 35 year old trailer queen, it won't end well.

Q17: If you had to compare the Texas T/A Mufflers to Fl*wmasters in sound & sound level, which kind do they sound like?

A:  If I had to compare them, I would say they sound a lot like the 40 Series. They have the same deep tone, just not as loud at idle, but when you step into them, they open up. Our mufflers don't have the "ringing" noise associated with the Flows. Most people tell me they sound better than the Flows and they LOVE the ADDITIONAL ground clearance.

Q18: Are you open on Sunday?


"Restoring Old Dreams"

Owner and Operator, Mr. David Mars
Serving the community since 1991
4588A Kennedale - New Hope Rd.
Fort Worth, TX  76140

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All rights reserved. Duplication only with prior approval.
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