This strikingly handsome '70 Trans Am was purchased in 1988 by its present owner, Steve Coombes. With matching numbers and a potent RA III 400, Steve's original efforts went toward restoring the vehicle. After a few years, the"novelty of a 'daily driver'...was replaced with emphasis on performance and drag racing," according to Steve. What Steve was after was a stock looking drag car. The TA slowly evolved into its present state, going through myriad performance modifications along the way.
Steve's Trans Am (in one of its earlier performance configurations) was campaigned and briefly held the ET and MPH record in NMCA F Top Stock. It was also the '95 and '98 class winner at the Pontiac Southern Nationals. Up until recently, the car retained all original sheet metal. However, the car now sports a brand new lightweight fiberglass hood and bumper. The car has yet to be strip tested at this reduced weight. Steve has done an amazing job with every aspect of this car. Craftsmanship is the word.
To the left is the TA's engine compartment which is just plain immaculate. By the way this is a number's matching 400 block that Steve has converted into a 455. Intricate machine work was performed by a crank specialist to permit the use of the big crank in the 400. A more powerful engine is already "in the works," according to Steve. And it will replace this 400.
Although racing seats, safety harnesses, and a 6-point roll cage are now present, the interior modifications and upholstered seats were tastefully done to match the car's original interior. The 6 point roll bar looks like it should have been a factory option. The car is registered and inspected (Texas) and can be driven on the street for short jaunts to the store and during cruise nights.
Block 1970 RA III 400 with 4 bolt mains
Bore/Stroke 4.182" x 4.210" (462 cid)
Deck Height .000" (zero)
Heads 1969 #16 d-ports; valves 2.125" intake and 1.800" exhaust; 12.5 to 1 cr
Rocker Arms Crower SS, rollerized; 1.65 to 1
Pushrods 5/16"- 9.450" & .080" wall
Lifters Crower roller tappets
Crankshaft 455 crankshaft; machined to accept 3" mains of 400 block
Balancer BHJ Dynamics Inc. (BHJ)
Piston Rods Carrillo/ steel 6.625"
Pistons JE custom flat top
Rings Speed-Pro
Bearings Clevite 77
Camshaft Ultradyne roller; 264 intake/ 271 exhaust @ .050"; LSA 108; lift of .689"
Timing set Cloyes
Intake/Carb Edelbrock Victor, single plane; Carb Shop Stage III 750 (926 cfm)
Fuel delivery Electric- Holley Blue (2 total); Mallory 5 port regulator; Jaz 16 gallon fuel cell with sending unit; runs on race gas only
Gaskets All FelPro except the intake which is made by Specialty Component Engineering, their p/n 128103 is slightly larger than most at 1.170" wide and 2.320" high. The heads & intake are port matched to this gasket size.
Water Pump Meziere electric
Exhaust Hedman with 1 7/8" primary and 3.5" collectors into mandrel bent pipe; Dr. Gas X-type crossover into Walker Race Magnum mufflers
Ignition MSD distributor; MSD 6AL box, blaster coil, and MSD crank trigger
Oil Pump Melling MS54D; Canton 7 quart pan, crank scraper, and OEM windage tray
Oil 10w-30 Mobil 1
Transmission TH400 with manual valve body and deep pan; A-1 Automatic Transmissions 8" torque converter, 4200 stall
Rear End/Gears GM 12 bolt with Moser axles, C-clip eliminator; Auburn limited slip with 4.33 to 1 gearing; T/A rear end girdle
Other All reciprocating parts balanced
Power Dynoed at 626 hp @ 6400; torque, 611 @ 4900;
Chassis Mods 6 point roll bar, sub frame connectors
Suspension Landrum 300 lb./in leaf springs with Cal Tracs traction bars; and Competion Engineering drag shocks, front and rear; all sway bars removed; Moog 6 cylinder front coil springs
Tires/ wheels 26-7.50-15 M/T Sportsmans mounted on American Torque Thrust rims; Either McCreary L-60-15 D.O.T or 28-10.5-15w M/T slicks
Brakes OEM, front disc, rear drum
Car Weight 3790 lbs. race weight
ET/speed 10.79 second 1/4 mile @ 123.55 mph; average 60' time is usually around 1.54-1.55 seconds. No current ET with lighter fiberglass hood and bumper.
2001 Performance Update: Steve's new 450 cid engine
Copyright © 1997-2001, Bill Boyle. All rights reserved.