"Better look again: It's not your son's LS1," read the sign attached to the raised hood of a Fourth-Gen Firebird at the POCI Nationals a few years ago. Streams of enthusiasts gave the car nothing more than a casual glance and concluded it to be another ho-hum Firebird before wandering down the aisles in search of their favorite classic musclecar.
For the keen-eyed observer, something wasn't right. Hold on-that's not an LS1 or LT1 under the hood, but rather a traditional Pontiac engine! Expertly crafted fuel-rail covers effectively hid the telltale classic Pontiac four-bolt valve covers. A closer look at the Bird's interior revealed a steering wheel and center console that were original equipment on '93-'97 FirebirdS and didn't match the '98-'02 front end or taillights. The paint and graphics-though reminiscent of a 30th Anniversary '99 T/A-closely recreate the '69 T/A. With so many conundrums, the question remained, what year of Firebird or T/A was this and what really lay under the hood?
MetamorphosisBeginning life as a '94 Firebird Formula, Jonathon Carter picked up the used F-body in 2001. A modified, carbureted (yes, carbureted!) LT1 sat between the fenders, backed by a nonstock 700-R4 trans, while in general, the Pontiac was in a sad state.
As the manager of Master Machining, an industrial machine and fabrication shop in the Wilmington, North Carolina, area, both the machinery and knowledge were there to convert the Bird to traditional Pontiac power. According to his father, Jimmy, the owner of the shop, "Jonathon and his longtime friend Anthony Gurganious decided that a traditional Pontiac engine conversion would be unique. Since Jonathon had a 455 from another project and since our shop has the aptitude and the ability to fabricate almost anything in-house, we decided to tackle the project."
Converting to a traditional Pontiac engine wasn't as difficult as most people would envision. After removing the LT1 engine and motor mounts, the 455 was lowered into the engine compartment where it was determined that the cowl would have to be trimmed back about 2 inches. Once complete with the cowl modifications, '67-'69 two-bolt motor mounts were bolted up, and then custom motor-mount brackets were welded to the frame to position the engine so the bellhousing was in the same exit location as with the LT1. From there, it was a matter of creating an adapter plate to mate the Pontiac engine to the 700-R4 and modifying the Edelbrock Torker intake manifold to fit under the hood. After notching and reboxing of the factory crossmember, R/A-III manifolds were used to expel the exhaust. Traditional Pontiac electronics featuring an HEI distributor lit the engine's fire.
According to Jimmy, "The car ran well, but the carbureted 455 was a race motor, complete with ported No. 16 heads and high compression. Combine the high weight of the iron-block and a radical camshaft, and the Firebird was less than an ideal street car." At this point, Jonathon and Jimmy agreed to trade vehicles, with Dad taking the keys to the Firebird and Jonathon getting Dad's original '88 IROC-Z convertible.
After driving the combination for a while, the new owner wanted to take the Bird to the next level, namely to create a fuel-injected traditional Pontiac that looked factory. According to Jimmy, "Jonathon and I discussed converting the engine to multi-port fuel injection, but back in 2001, Pontiac-specific fuel-injection kits weren't available, so our only viable option was to retrofit a mass-marketed fuel-injection system onto the Pontiac."
A Fuel-Injected Pontiac Engine After extensive research, the Carters worked with Fuel Injection Specialties in San Antonio, Texas, to convert a '90 Corvette TPI system for the classic-Pontiac mill. Using a supplied custom harness, a Pontiac HEI distributor was modified to accept the Corvette seven-pin electronic module to provide the spark. Rather than convert a traditional carbureted intake to EFI, a TPI-style steel sheetmetal intake was fabricated (which was named TribalFlow Gen 1), along with custom fuel rails to create a low-profile intake that could utilize the TPI speed-density-based electronics, including a MAP sensor, a GM in-line fuel-pressure regulator, and 24-pound fuel injectors. After topping the intake off with the Vette's 52mm throttle body, a custom chip was burned, and a freshly built R/A-III 400 engine was eased into the bay. Although the engine started right up and ran well on the streets for over a year, Jimmy really wanted a lighter engine combination and a manual transmission.
The Short-Deck ComboHarkening back to the original T/A, what if Pontiac had mass-produced the 303 short-deck engine to compete with the Chevy and Ford 302s on the street? What better than a modern T56 transmission and a high-revving classic Pontiac? Since a 303 is as rare as hen's teeth and required many specialized parts, Jimmy went with a more readily available short-deck 301 powerplant.
Introduced in '77, the Pontiac 301 engine was never intended for extreme duty use, though the turbo 301's block for '80-'81 was strengthened in several areas. With a full 1-inch-shorter deck height and the ability to bolt-on traditional Pontiac heads (which require a custom intake), Jimmy hoped the engine could be built to displace approximately 350 ci and spin into the stratosphere.
Starting out life as an '80 Turbo 301 block that carried a 4.0-inch bore by 3.0-inch stroke, a stroker short-deck combination was crafted that resulted in a 359ci combination when factoring in a 0.030 overbore. A Pontiac 400 crank was chosen and sent to Edward's Auto Machine in Wilmington, North Carolina, where the 2.25-inch rod journals were reduced to 2 inches, and the crank was destroked from 3.75 to 3.52 inches. Back at the Carter's shop, the crank counterweights were turned down nearly 51/48 inch to provide proper clearance and reduce weight before the rotating assembly was balanced. Using the 400 crank also helped cure an inherent weakness of the 301-the 301 crank features only two counterweights to save weight, while other Pontiac V-8 cranks have six counterweights.