It always warms the recesses of our little black hearts when we find a story like this. It’s a gut check. It’s a reality check. It’s what this hobby is really all about. Not a pile of parts, but a pile of people who make and massage them. It’s Dave Gehrke doing his damndest to keep it all honest and adhering to the basic tenants of the life: Do as much as you can with what you’ve got, and what you don’t, you noodle out, create, and put together (with maybe a pal or two) in the comfort of your environment.
Dave bought this ’72 in 1987. It’s been defiled, mocked, and fortified with several big-blocks since. He even toyed with idea of slinging a Duramax between the rails. Then he went for an LS engine. The conversion was done long before there were any aftermarket assemblies to ease the process, so he called on his high school buddy Tom Izzo at Speed, in nearby Schaumburg, Illinois. The cherry was an iron-block 6.0L LQ4 that once plodded mundane in a van. He ran the car normally aspirated but planned to turbocharge it one day. In that configuration (325 hp and 370 lb-ft of torque), it tripped the beams in (yawn) 13.63 seconds.
Clearly, this performance caliber did not excite. At the time, Dave didn’t have any fabrication skills or the tools to perform them, but forged ahead full of Monster. “The following off-season, I bought a welder, a chop saw, and other tools and started the turbo install,” he says. “The original plan was to put a single turbo on, but I got a screaming deal on [Borg-Warner John Deere agricultural] turbos and could not pass them up. With 15 psi on the stock short-block, the car ran mid 10s the second season out. Since then, the short-block has been upgraded to max out the turbos … Each one is capable of 550 wheel horsepower, so I figure there is another 100 wheel horsepower to be had with some more boost and timing.”
His best 60-foot time is an agonizing 1.82 seconds and the best quarter came up in 10.53 at 135 mph. The problem isn’t lack of bite but the rather slow spool-up time the turbos require with an A/R of 1.22. The A/R denotes the rated volumetric efficiency of the turbocharger’s two sections—compressor wheel (engine boost) versus the turbine wheel (that drives the compressor from the exhaust). A large numerical A/R takes more time to spool up than a smaller one. A relatively small engine displacement such as Dave’s 370 would accelerate quicker with an A/R anywhere from 0.48 to 0.63 and an rpm range of 3,000 to 8,000. “There’s also more power left in the tune-up with good gas and more boost,” he says. When he’s wrung all there is from the industrial snails, he plans to upgrade the hardware.
What’s one of the things he likes the most about his combination? The flies it draws. “Every time I go to the track and make a pass there is always a crowd around it. It is so quiet with the cast-iron ‘mufflers’ [exhaust manifolds] on it that no one has a clue how fast the car really is.”
Dave says that the build wouldn’t have been successful without the help and nourishment lent by his friend Jim Norman and the staunch support of his wife, Tracey. He had thought of selling the brown bag after his daughter was born, but his wife talked him out of it. Lovely woman, Tracey is. “Jim and I spent countless hours drinking Monster and Newcastle Brown while working on the car. The hobby wouldn’t be one without like-minded people, and in Dave’s realm that includes Larry Hamilton, Jim Moran, and Dan Marks—guys who Dave would call regularly for advice and wisecracks, and Chuck Johnson at Finish Line Transmissions in neighboring Wood Dale. Nice going, lads. Everybody else take notice.
In the misty future, Dave sees some big brakes, more suspension, and to be threading the autocross needle with his sleeper.