When it comes to cars, there are sometimes unsung heroes that enthusiasts never hear of. We're referring to the cars behind the scenes, vehicles known in the industry as "test mules" that are used to try out new parts, engines, and safety equipment/designs. From validating a new engine (or crate motor) to being sacrificed as a crash test vehicle, mules sometimes have long lives in the service of making things better for enthusiasts.
Our feature car is one such warrior. Owned by GM Performance Parts' Bill Martens, this car started life as a plain-Jane, 307 V-8 powered, Malibu convertible. When it rolled off the line in 1970, GM's assembly line workers surely had no idea this car would achieve the fame it currently enjoys. For the last dozen years, the Malibu has served as an engineering mule car, testing crate engines and other performance parts for the GM Performance Parts program. This same car was used to validate the now famous ZZ4 crate engine, the Ramjet 350, the Ramjet ZL1, the 502 crate engine, and the new ZZ 572 monster big-block.
Most test mules aren't treated very well, and Bill's Chevelle is no exception. The expression "rode hard and put away wet" applies. When GMPP was ready to debut the new 572 engine, it wanted an appropriate "wrapper" to show off the new crate engine. Bill's Chevelle got the call.
As plans were being made to restore and update the car, Rides TV came calling. The TV guys were looking for the right subject vehicle for a show segment, and they quickly targeted Bill's Malibu for their programming. After the details were worked out, the car was sent to Washtenaw Community College in Ann Arbor, Michigan. Working with WCCC, the gang in the Custom Concepts and Cars group went to work updating and repairing the venerable A-body.
While most of the car was in good shape, the doors and bumpers needed some extra attention. Year One, Inc. got the call for sheetmetal for the Malibu. As the exterior of the car was being worked on, the interior was also getting a full revamp. The stock Malibu seats were dumped in favor of a pair of extra-comfortable 2004 GTO eight-way power buckets. Along with the seats, the dashboard received a few minor modifications to accept an Eclipse stereo system with navigation and CD/DVD capability. Although it remains true to its 1970 heritage, this car has some 21st-century techno-pop. The dash was finished off with brand-new GMPP gauges, and the OE steering wheel cleaned up and put back in place. After that, the entire interior was done in a stylish and comfortable leather/suede combination.
Once all the bodywork was complete, the paint crew at Washtenaw CC took over and treated the car to a full spray of PPG "Oh So Orange" with a full clearcoat treatment. The result was a car that pops like a supernova in the sunshine.
At the heart of this rechristened Chevelle is GMPP's new pride and joy, the ZZ 572 crate engine. Available in both low- and high-compression versions, this motor makes enough power to send the Ford guys crying to mama and make the Mopar guys wet their pants. The milder (milder in this case is like comparing King Kong to a pet store spider monkey) ZZ 572 features a .632-inch-lift single-pattern hydraulic roller cam, 1.7-ratio aluminum roller rockers, high-flow aluminum heads, and a single-plane aluminum 4 bbl manifold. The low-compression (9.6:1) 572 pumps out 620hp at 5,500 rpm and 650 lb-ft of torque at 4,500 on 93-octane gas. That's a plenty stout yet streetable powerplant by any measure, but if that's still not enough grunt, the high-compression version boasts 720 ponies. Two more reasons why you just gotta love a big-block!
Keeping the big-block cool fell on a Be Cool aluminum radiator. The Be Cool system kept th
The ZZ 572 comes complete with a carburetor and GM HEI electronic distributor, so all you have to do is drop it in and turn the key. GMPP's crate engines feature generous 12,000-mile warranties, so if any problems should come up, you've got some protection. Also, all of GMPP's crate engines use brand-new parts. No remanufactured or junkyard reclaimed items are used in any of these engines.
Transferring the power to the wheels is a GM 4L85E transmission equipped with a 3,000-stall speed TCI torque converter. The wonderful thing about the 4L85E (say that five times fast) is that it bolts up to the stock TH350/400 crossmember. Shifting chores are handled by a pirated '99 Camaro unit. From there, all the ground-pounding torque and horsepower goes to a GM 12-bolt rear with 3.23 gears, DTS high-strength axles, and a Detroit Locker differential.
To make sure this A-body can stop after unleashing the 572's power, Bill installed a four-wheel disc Stainless Steel Brakes system to increase the big Chevelle's whoa power.
Because the car was being featured on Rides TV, a 90-day deadline was looming over the crew at Washtenaw CC to get the car finished. To their credit, they only went over the deadline by 10 days. Some might balk, but when it comes to car projects, 10 days is nothing, and the quality of work suffered not at all. Every seam, panel, and piece of trim is nearly perfect on the car. The convertible top is a flawless piece of art, operating smoothly and giving the car a good seal against the elements.
Right after the Chevelle's completion it went straight to the test track to put the 572 through its paces and see how the newly restored car handled. After a few more tests, the Chevelle traveled to Florida to long haul on the 2006 Hot Rod Power Tour. Through 2,000 miles of constant cruising and 100-degree heat, the car never missed a beat, the ZZ 572 big-block staying cool and happy thanks to a Be Cool aluminum radiator, along with the car's driver and passengers.
Chevelles and Malibus are plentiful, and it might be easy for all those to start blurring together in some hellish A-body Rorschach test. However, this car stands apart from its peers. The combination of subtle style, classic looks, neck-snapping power, and striking paint allows this one to easily stand apart from the crowd.
To see all the great performance parts they have to offer, visit the GM Performance Parts Website
Car: 1970 Chevelle Convertible (started life as a Malibu)
Trans: 4L85E Automatic w/ overdrive
Rear: GM 12-bolt with Detroit Locker Differential w/ 3.23 gears, DTS axles
Brakes: 4-wheel slotted disc Stainless Steel Brakes system
Front - Global West coilover system w/ 1" drop;
Rear - Stock coil spring with Hotchkiss control arms and swaybar
Wheels: Front - 18 x 9; Rear - 19x10 / Goodyear Eagle F1 Tires
Stereo: Eclipse CD/DVD capable with GPS navigation system
Gauges: GM Performance Parts
The heart of the GMPP Chevelle is the new ZZ 572 crate engine. With 620 chest-thumping hor
ZZ 572 ENGINE SPECS
Displacement: 572 cid
Bore x Stroke: 4.560 x 4.375
Block: Cast iron w/ 4-bolt mains
Crank: Forged steel
Rods: Forged steel - H-beam design
Pistons: Forged aluminum (9.6:1 compression)
Cam: Hydraulic roller; Lift - .632 int./ .632 exh.
Heads: Aluminum rectangular port, 118cc chambers
Valves: Stainless steel - 2.25 Intake / 1.88 Exhaust
Rocker Arms: Aluminum roller design - 1.7 ratio
Intake: Single-plane aluminum
Carb: 850 cfm 4 bbl
Ignition: HEI-type Distributor
Horsepower: 620 @ 5500 rpm
Torque: 650 ft./lbs. @ 4500 rpm