Thrasher Camaro Part I - 1969 Chevy Camaro Restoration

Mark Stielow Builds a '69 Camaro to Thrash!

Mark Stielow Jan 1, 1998 0 Comment(s)

Step By Step

The Thrasher is intended to perform as well as a modern musclecar through the use of simple modifications and aftermarket bolt-ons. It is being built to drive on the street, compete in the One Lap of America, drive on the Hot Rod Power Tour, and more.

The basis for the Thrasher is a mostly rust-free Southern California '69 Camaro with 120,000 miles on it. Equipped with a built 350, TH350 trans, and 10-bolt rearend, it cost $2700.

Stielow gives the thumbs up on another project. He's happy because this Camaro is essentially complete, though it has been a street machine the majority of its life, with many modifications and lots of miles.

The interior really showed the wear and tear of the mileage. All of these components will be replaced with D&R Classic Automotive repop interior pieces, a Momo steering wheel will be installed, and a Hurst shifter will be added for the Viper T56 six-speed transmission. Bucket seats from Keiper/Recaro will hold the driver and companion firmly in place as the thrash ensues.

After carefully draining the radiator into containers (don't dump coolant on the ground) and removing the radiator, Stielow pulls the engine and transmission out of the Camaro. This hoist is available from Summit Racing for a paltry $179.99 and is well worth the money if you plan on making a habit of swapping engines.

Something you might consider is to clean up your project vehicle, even if you plan on repainting it. Stielow rubs out the paint to make working on the Thrasher a little more rewarding.

The 406ci engine will be fully detailed in next month's issue of CHP. It is an engine that anyone could build and will make between 450 and 500 hp all day long. Stielow has plenty of experience with the single-plane Accel/DFI system--doing the mapping of that system and getting it all set up is a story in itself.

Built to handle the more than 450 hp of the small-block, the Viper T56 transmission looks a little different externally than the Camaro/Corvette T56, and this one is even more different, as Stielow installed a Chevy input shaft to make it work with his car's engine.

Big wheels and wide rubber fit the bill for the look and performance of the Thrasher. Stielow will run BBS RK wheels (18x8.5 inches up front and 18x10 inches in the rear) and BFGoodrich Comp T/A tires (245R40-18 up front, 295R40-18 in the rear) on the street and may switch to 17-inchers when racing (the tire companies don't have the really trick rubber in the 18-inch sizes yet).

A stock TH400 trans mount is cut up and tubing is used to modify it to mount the T56 transmission. A factory mount is used, as the legs of the mount kick up to provide extra room for the exhaust (this car will be low, so the higher the exhuast can be the better).

Editor's note: If you don't know the name Mark Stielow, you will after reading the next few articles on what it takes to transform a first-generation Camaro into a Pro Touring performance car. And he should know. Among the many Camaros Stielow has constructed, two should be very familiar to our readers. In his first serious effort, Stielow built a white '69 Camaro that integrated numerous OEM components and won Car Craft's Real Street Eliminator back in 1993. Being a young man with limited means and many ideas, Stielow sold the white car and followed it up with a spectacular red '67 Camaro powered by a GTP engine, which won Hot Rod's Hot Rod of the Year in 1996.

A Stielow car is evidenced by strong acceleration, killer braking, and wind-shearing top speed--the true definition of a Pro Touring car. Stielow has reached for the Holy Grail of ultimate first-generation ponycar performance with each of his cars and has learned plenty of lessons along the way. CHP will document the buildup of his latest car, the Thrasher, so you can all see what Stielow does to make his Camaros perform like modern performance cars. With the details provided, you will be able to reproduce this performance in your car. Then you'll understand the lure of the Pro Touring hot rod. --J.S.

Every Camaro I have built was always intended to be driven. Building cars is exciting, but I truly enjoy driving them. I'm a little hard on equipment, so in jest I've decided to call this latest '69 Chevy Camaro the Thrasher.

The last few Camaros I've built were essentially designed to run in one event, the One Lap of America. A good side effect of building cars for that event is that they have to be docile, daily-driver street cars that can rip if you need them to.

In case you don't know about One Lap, it's a weeklong trip around the country, usually covering about 6,000 miles or more, where competitors drive their cars from one racetrack to the next and run against the clock on the track. It is one week of sleep deprivation and long hours behind the wheel, so to participate you better have a ride that is both comfortable and a strong performer.

Besides the One Lap, I like to run Hot Rod's Power Tour and occasionally blast out to the local road-course racetrack on open practice days to have some fun. To do all this and enjoy it, you need a car that not only performs great but is very dependable and simple in its construction. This is why the Thrasher is going to be rock-crusher simple, yet run as quick as a finicky race car.

The Plan

If you are going to build anything, be it a hot rod or a skyscraper, you need a plan, so here's what I've laid out: I want to build a first-generation ('67-'69) Camaro using as many bolt-on, off-the-shelf parts as possible. The drivetrain will consist of a 406ci small-block engine, a six-speed OEM transmission, and a 9-inch rearend. The suspension will contain a few race-bred ideas and parts but will be essentially the factory setup with premium-quality components. I like huge-by-large disc brakes with equally fat wheels and tires around them, not only for their looks but for their performance.

While building my last car, a '67 Camaro, I discovered that '67s have smaller wheelwells then '69s, so I'm using a clean '69 Camaro as the basis for the Thrasher. It eliminates the need to mini-tub the car while still running big rubber out back--a serious savings in cost and headaches.

I will be using components on the Thrasher that were on the last few Camaros I have built. I've tried a lot of aftermarket components and can truly say my cars have performed best with ACCEL/DFI electronic fuel injection, Baer brakes, Koni shocks, a Currie rearend, BFGoodrich tires, a Borla exhaust, Vintage Air A/C, and Griffin radiators. I will be using these components again, along with other aftermarket parts and a sprinkling of OEM parts.

Department of Motivation

The buildup of the 406ci engine will be covered in next month's issue, but here are the basics. I started with a cast-iron Summit/Bow Tie block and added a Cola crank with Trick Flow rods riding on Federal Mogul bearings. The rods are pinned to Wiseco pistons using Speed Pro piston rings. A pair of Edelbrock aluminum Victor Jr. cylinder heads are fed fuel through an ACCEL/DFI single-plane EFI manifold, while a Crane roller valvetrain with Ferrea valves controls the flow.

The power from the engine will run through a Viper Borg-Warner T56 six-speed transmission that I have modified with a Chevy input shaft. The Viper box has a larger output shaft, which can handle more horsepower than the Camaro/Corvette transmission version. That's a plus, because I expect the engine to make at least 450 hp.

The factory pull-off clutch and hydraulic clutch actuator are good designs, so I'll use a Centerforce dual-friction pull-off clutch and '96 Camaro hydraulic clutch actuator assembly. Mounting the clutch actuator at the firewall is a little tricky, as the factory firewall-mounting surface on the late-model Camaro is at a severe angle. To correct this, I fabricated a simple bracket out of 1/8-inch sheetmetal, which is shown in the photographs.

Cutting the hole for the shifter is not difficult but should be done with patience so it is as small as possible.

The rear mount for the T56 trans is a little involved. It was fabricated from pieces of a TH400 trans mount and some tubing. The T56 was mounted to the back of a mockup engine and supported in place by a jack. The pieces were cut and welded together until the transmission mount was done. To determine the proper location for the T56 transmission, I measured where the factory automatic-trans output shaft was located and put the output shaft for the T56 in the same place. This seems simple, but if you pull the factory trans before doing the measuring, it's a little tougher.

The rearend is a stock-width Currie 9-inch with an aluminum center section. One-inch lowered Eaton leaf springs bolt into the stock mounts. This was all done for simplicity. I have built cars with custom rearends and suspensions and found they don't make enough of a difference to justify all the work. The leaf-spring suspension can be tuned to a outstanding level of performance with bolt-on components.

Custom Work

After the engine is detailed in the next issue, we'll get down to some of the fabrication work performed on the car, like the exhaust system, the four-point rollbar, the subframe connectors, and more. I'll try to be as detailed as possible about the materials used, the tools required, the dimensions, and more, so that if you want to make these parts or have somebody make them, there's enough information to do so. Check out the engine buildup and dyno tuning next month. CHP

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