LS1-Powered 1984 Pontiac Trans Am - Richter Scale Road Ripper

Drivetrain
When determining the drivetrain config-uration, Flannery went back to his inspiration-a '92 Firebird he saw at Hawks Third Generation. "I ordered a Tubular K-member like I saw in the company's show car," he says, "and I asked Bruce at Hawks how he had done similar conversions."

The drivetrain for the '84 came complete from a wrecked '98 T/A. It features the LS1 cast aluminum block with 6-bolt, cross-bolted main caps and a 3.9x3.62 bore/stroke. A GM nodular iron crankshaft, powdered metal steel connecting rods and hypereutectic aluminum pistons make up the rotating assembly. A ported oil pump from SLP provides high pressure and high volume oil delivery. The heads are No. 853s that were milled 0.008 by Back's Cylinder Head Services of Lexington, Kentucky, to ensure a flat surface and raise the compression ratio to 11:1. That's slightly higher than the factory compression of 10.25:1, while still allowing the Trans Am to drink premium pump gas.

Comp pushrods activate GM 1.7-ratio rockers that compress Patriot Dual Gold springs to open and close GM 2.00/1.55 valves. The valvetrain is directed by an LG Motorsports G5X2 roller cam with 232/240-degrees duration, 0.595/0.608 lift and a 112-degree LSA.

Flannery retained the stock MAF and 75mm throttle body. In the Fourth-Gen transplant's ignition system, spark travels from distributorless coil packs to Taylor 9mm wires and NGK TR55 plugs. Exhaust exits from Hawk's stainless steel long-tube headers, featuring 1 5/8-inch primaries and 2 1/2-inch collectors, and ends in 2 1/2-inch turndowns.

Air is fed from a component-style custom air intake tube, supplied by Spectra Performance, and consists of a rubber 90-degree elbow, various tubes and reducers and a stainless steel cone air filter. "I like the modular components of this product because it allowed me to build the air intake system myself," Flannery says.

Mounting a Fourth-Gen drivetrain into the Third-Gen was simple, according to Flannery. "The Hawks K-member is a great design. I lowered the LS1/T56 onto the K-member and bolted it into place. Then I raised the entire drivetrain underneath the '84 T/A and attached it to the unibody. Next, I bolted in a Spohn T56 crossmember with trans mount and safety loop and a Spohn adjustable torque arm-and the drivetrain was fully mounted and ready to wire."

To efficiently deliver the power rearward, Flannery used a Spec Stage II single-disc clutch and steel flywheel. An aluminum Fourth-Gen driveshaft was employed and he installed a narrowed '98 T/A rear after adding Ford 9-inch housing ends, a Moser stud girdle, 4.10 gears to the stock limited-slip unit, and Moser 33-spline axles.

The next step of the project was the fuel system, including minor modifications to a '98 T/A fuel tank. "I had to remove two inches from the neck of the tank and mount it back to its body with a rubber hose and clamps-it now fits perfectly in the '84." He also installed a Racetronix 255 lph electric fuel pump in place of the OE unit. Using the entire fuel system from the LS1 allowed Flannery to transplant the LS1 engine into the '84 T/A without much modification except for an "owner's choice" LS6 intake with stock 28-pound injectors. "I used a Corvette C5 fuel filter, which is integral with two fuel lines, a send and a return, and mounted it to the underside of the T/A near the framerails," he says. He ran a braided-steel AN fitting line underneath the Trans Am and forward to the engine's fuel rails. "The fuel system thinks that it's still functioning inside of a Fourth-Gen Trans Am. It can't tell the difference.