Great Story on a 1969 Yenko Camaro
Undoubtedly, the '69 Camaro has become one of the most popular, coveted, singled-out, hands-down favorite hot rods of all time, right up there with the Deuce coupe and Tri-Five Chevy, and as such it represents the core of many aftermarket businesses
. Nobody knows this stuff better than Darryl and Peggy Nance, owners of D&P Classic Chevy in Huntington Beach, California.
Darryl is old enough to remember the original F-body and all the smoke and glory that went with it. He loved the Yenko COPO 9561 (L72 427 rated at 425 hp). Forty years hence, he's created a Yenko tribute car without using a single original part. The aftermarket had everything he needed to make this project come alive, hence everything is as new as it would have been from the assembly line, including the body itself. But it just didn't fall together.
"Our goal was to build a car that could be used daily. The theme was if Don Yenko was building a car today, what parts would he use? That meant a contemporary engine, an LS iteration not a carbureted big-block that was never certified in anything. On top of that, we wanted a mid 11-second potential and road-course handling married to at least 20 miles per gallon
. We wanted to use the best stuff in every area of the car.
"We got a Dynacorn body from major project partner Classic Industries for this build after the donor we had originally showed way too much monkey business once we'd stripped it down. The Dynacorn is in the neighborhood as far as fit and finish is concerned but we needed to tidy it up before going further. Our other primary partner in this venture is Original Equipment Reproduction (OER) in Westminster. They supplied all the trim and functional equipment we needed to complete the car."
Darryl had contemplated an LS9 blower engine but decided that Yenko would have thought it cost-prohibitive. In place of the old iron 427 that the Yenko would have had, he used a 427ci LS7 crate engine for the go-button. That it's normally aspirated fit the image better, too. Since "green" is the watchword these days, the new GM Performance Parts E-ROD engine program was initiated at the '09 SEMA show. The first incarnation is a 430hp/376ci LS3 crate accompanied by all emissions controls and calibration ECU for retrofit. It has been certified by the toughies at the California Air Resources Board (CARB) for use in any car, regardless of year. Until now, the recipient had to be at least 30 years old to avoid the mandatory 2-year emissions certification. Without question, GMPP will provide similar equipment for other LS engines as well, including the LS7.
What else would Yenko have included? Since Don was a road-racer, he'd have insisted on a completely modern suspension system, perhaps one centered on the produce of Detroit Speed, Inc. Bigger brakes would be a natural, as big as could fit behind those 18-inch hoops and outsized, high-traction rubber. Though you could order a COPO Camaro with a Turbo 400 automatic, Yenko would have demanded a manual transmission for its overall flexibility and gear ratios to make the most of that 4.10:1 ring-and-pinion.
"The other twist on this is that GM used our tribute Camaro as their poster car at SEMA," said Darryl. "It was the only muscle car that they invited and became the roll-out car for the GMPP E-ROD program. If you use all the parts and components in the kit you can get a smog certification. It's good for me and for the guy who's got an '85 Monte Carlo who was basically screwed before. If you follow these criteria you're guaranteed to have a smog-legal car that far exceeds the emissions and the power of what the car came with originally. Even though our car has an LS7, it meets the criteria and GMPP will roll that complete package out very shortly."
Motor & Drivetrain
Darryl streamlined the exhaust flow with Lemons 2-inch primary pipe headers and 3.5-inch collectors that neck down to a 3-inch stainless exhaust tubing interrupted by Flowmaster Super 44 muffs. Otherwise, the engine is untouched. He included a GMPP accessory drive system, computer harness, et al that depends wholly on a Kinetik high-performance battery. Would Yenko have included the dry sump oiling system? You bet, red rider. Darryl made it all work with Peterson Fluid Systems equipment and the LS7 oil tank and ancillaries. Engine coolant is cycled and managed by a Be Cool radiator and twin push fans. Though the 427 is factory rated at 505 hp at 6,300 rpm and 470 lb-ft of torque at 4,800 rpm, Darryl figures the underrated engine makes more like 540 hp in a 3,300-pound envelope. However, for the roll-out, the engine was saddled with less-than-optimal LS3 exhaust manifolds with pre-cats and cats and four oxygen sensors. The immediate future will include slicker LS7 manifolds for the full-on green conversion and Darryl is working on that with GMPP right now. Despite serious wheelspin, drag testing revealed 12.50-second elapsed times at 118 mph, more or less confirming his power guesstimate. A sticky tire would shove this job straight into the mid 11s with nary a drop of sweat or blood. Lucky guy got the first Tremec T56 Magnum transmission ever built, worthy of at least 700 lb-ft. He put an LS7 flywheel and clutch assembly behind it, collaborated with Shafi Keisler on his conversion package for the bellhousing and hydraulic linkage, whipped up a driveshaft, and hooked it to the Moser 12-bolt (33-spline axles).
The theme is green. Undoubtedly, there's some recycled steel in the brand-new repro Dynacorn body provided by Classic Industries. The paint is therefore water-based, in this case, PPG Silver Ice Metallic stolen from the '10 Camaro palette. OER provided every bit of the exterior trim, including the Yenko badges, ZL2 replica hood, and the Z/28 spoiler. As you can see, D&P spent many hours perfecting the surface of the metal.
Since this exercise was more about fitting modern power to an older vehicle, the Yenko tribute's interior looks pretty much like it would have in 1969. OER supplied Darryl with a COPO 140-mph speedo, a Z/28 tachometer, and no less than 224 additional trim and working parts. Since the stock seats are flatter than boards and would slide you right out the door if they could, Darryl specified Pro Car seats. Stitchcraft Custom Interiors in Westminster did up the buckets and the bench seat to match. As a real road car, HVAC was mandatory, in this case a Vintage Air system. Tunes? He's got 'em. A full-on, though discreetly placed, system winds from a Clarion stereo head through Kicker speakers. He put a Line-Loc on the Hurst shifter poking from the repro console/gauge pack just as it would have been in the old days.
Here, DSE rules. The key to this car's handling and suspension changes is the subframe which is designed around C6 Corvette spindles. The front package includes the rails; rack steering; modified steering knuckles; Delrin bushings; tubular upper and lower control arms; coilover shock absorbers; a hollow, 3-piece, 11/4-inch splined anti-sway bar; and solid aluminum body bushings. Marching to the rear, we find DSE mini-tubs bookending DSE's QUADRA Link suspension, Koni aluminum-body adjustable coilover shocks, upper shock mount crossmember, Panhard bar, and high-durometer bushings rather than Heim joints. Darryl tied front to rear via subframe connectors.
Wheels & Brakes
Darryl designed the D&P wheels specific (as yet to be named) and paired them with BFG KDW 2 rubber. The 18x8s carry 275/35s while the big, back 12-inchers sling 335/35s, thus ensuring a maximum contact patch. The dark centers aptly promote the Baer Pro-Plus braking system with 6P calipers and 14-inch plates at all corners. ABS Power Brakes in Orange, California, supplied the master cylinder and matched it with a special accumulator.
D&P Classics' Yenko 427 Tribute Signifies The First Of The "Green Motor" Conversions
From the March, 2010 issue of Chevy High Performance
By Ro McGonegal
Photography by Henry De Los Santos