When you spend 31 years racing the same car, you amass a knowledge base on that car like no one else. You know every nut and bolt-which ones will strip if you turn them 1/4-turn more, and every specialty fastener-and you know what works and what doesn't. Just like being married for more than a decade, you also know every blemish on your love, and have learned to overlook them. You've shared some of your best and worst life experiences together, and you know that there's more to your relationship than show-quality paint.
Keith Seymore has been racing this '74 Chevelle for 31 years, and his history with the car extends longer than that. His dad worked for General Motors for 35 years. One of the long-standing traditions of working at a Detroit automaker was ordering your new car every few years. Even to this day, people who really care about cars take special care to custom order their car exactly the way they want them. And if you can, you call in favors to make things happen that aren't on the options list. That's how you find cars decades later that defy what order books say was possible for that year-muscle car collectors have dreams about these sorts of things. When it came time to order a '74-model GM car for Keith's mom, his dad wanted a two-door Chevelle, but he wanted to add the police package goodies. He also wanted the opera window, which turned out to be the biggest challenge of the custom order. After working with the car order desk for weeks, they finally gave him the phone number of the plant manager and said to work it out with him. So he did.
Keith's mom drove the Malibu for four years, and then it was on to the next new GM car. And the Chevelle with the cop motor, cop suspension, and cop shocks was offered up as Keith's car to drive. In stock form, the car was pretty impressive, especially for a mid-'70s commuter. Even though the engine from the era of detuned V-8s, it was still a 454. The police package gave it the LS4 version of the big-block, which had a rating of 235 hp, an aluminum intake, and Q-jet four-barrel. The TH400 transmission had a performance valvebody, and the 10-bolt came with 3.42 gears and a posi. Eight-inch Corvette Rally wheels were also part of the deal, wrapped in HR60-15 Goodyear blue dot pursuit tires. Heavy-duty suspension and skid plates, beefy sway bars, and a gauge cluster that included a tachometer and actual gauges were also thrown in. One of the more interesting items was a performance console transmission shifter.
It didn't take long for Keith to find himself and the Chevelle at Lapeer Dragway, a local dragstrip that a lot of Detroiters make use of. The car in stock, 4,100-pound form turned a 15.10 the first time down the dragstrip. By the end of the day, Keith had quickened that to consistent 14.90s. And that was the start of a 31-year racing relationship with the car, and the start of a refinement process that continues today.
With a 4,100-pound car, there's a lot of weight to shed. Low-hanging fruit included the steel hood and the 60-pound front bumper. And behind the front and rear bumpers was reinforcement and miscellaneous fat that was worth about 50 pounds on each end. As Keith's relationship with the car lengthened, he got more and more refined in his weight-reduction tactics. He found that a 12-gallon gas tank from a Chevette would fit between the rear framerails, retaining a factory look and avoiding the need for a fuel cell. He started moving weight from the front to the rear, such as the battery. A two-core radiator holds less coolant than a four-core, therefore weighing less. And by some miracle, the car cools fine with a two-core radiator.
Keith ran the car for years before someone asked if it had one of those GM shifters that y
Weight reduction only goes so far, though. So the quest for more power began. Keith knew he would regret making changes to the car that would prevent it from being returned to stock if he ever decided to do so. Instead of tearing apart the original 454, he yanked it out and stuck it in the corner. He started on what would be a line of six big-blocks. The first couple were pretty mild steps up: A 482 and 462, based on production blocks. Then a 510 was built that launched Keith on a serious cubic-inch fetish. Next came a 572 and then a monster 624. That block cracked between the bores, ending that engine's stint in the car. While the 672 was out and the 555 was being built, Keith tossed the original 454 back in the car under the premise of keeping the trans and rearend lubed and healthy. Naturally, he worked a few races into that maintenance schedule. To show just how much a few hundred pounds of weight reduction and some precise chassis tuning and weight reduction is worth, the car turned a 12.25 e.t. with the original 235-horse engine in it. We have to tell you, we'd be embarrassed to get spanked by a boat with a smog motor in it!
The 555 that's currently in the car stepped things up quite a bit. Scott Williams at S&K Racing built the engine to make the most of the way Keith had his Chevelle setup. The engine uses Weisco 13:1 pistons with AFR heads and a Cam Motion bumpstick. Lukovich Racing handled all of the machining work on the Bow Tie block, K1 Technologies crank, and rods. A lot of the efficiencies in transferring that power to the ground come through the original TH400 transmission that was reworked by Jim Paquet of JPT. The gearbox uses a standard pattern, full-manual valvebody. This provides high-quality shifts on demand, but lets Keith retain the original shifter. The car has turned a best quarter-mile time of 10.001 at 136 mph with this powertrain combination.
The exterior's great looks are more accidental than intentional. The car has never been painted all at once. In fact, the roof and upper quarter-panels still wear the original black paint. Since the car was a daily driver for many years, the doors and rear-wheel openings rusted out at different times. The doors were replaced and patch panels welded in, and sections of the car were painted as needed.
Keith Seymore's '74 Chevelle is a great example of the potential that this era platform ha
This engine bay has housed seven different engines in its 36 years. The current 555ci engi