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The premier manufacturer and distributor of quality suspension and restoration components for 1960-1972 GM pickups, blazers, panels and suburbans.

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While the engineers at Chevy normally have our respect and admiration, the guy who thought that putting the fuel tank in the cab was a good idea should be smacked upside the head. As much as we like to sniff gas fumes, it's the chance of immolation that has us worried.

Luckily, the folks at Early Classic Enterprises have taken the initiative and produced this stainless steel tank that is designed to sit between the rear frame rails. Early Classic offers the highest quality, American-made tank that carries a full 23 gallons of high test.

The tank is constructed from heavy 14-gauge stainless steel and is much less prone to tearing, cracking and punctures than aluminum. Another plus of the Early Classic unit is that the tank is engineered to accept an in-tank fuel pump for fuel-injected applications or run with a factory external pump. It features internal baffling and includes an electric sending unit, as well as all necessary mounting hardware.

Early Classic Enterprises is based in Fresno, California, and is owned and operated by Dave Clark. Since its opening in 1993, Clark has specialized in parts for the '60-'72 Chevy and GMC trucks. In that time, he has turned Early Classic into one of the nation's premier manufacturers and distributors for parts for lovers of classic Chevys. Be they suspension, body or specialty, chances are Early Classic has the part you want.

GM Coils Vs. Leaf Springsand How to Build Stronger Arms

When it comes to '60-72 Chevy and GMC C-series trucks, there seems to be more myth than fact regarding the rear suspension systems. While some trucks came from the factory with rear leaf springs, others have coil springs and trailing arms. We've heard numerous stories over the years, and to help clear things up, we visited the experts at Early Classic Enterprises in Fresno California. Dave Clark and his crew have been building suspension components for the '60-72 GM trucks for close to a decade, and

their wealth of knowledge and experience is priceless.
We quizzed them in detail about the different chassis and suspension configurations, and here's a run down the facts: Prior to 1959, all GM light trucks were only available with a rear leaf spring suspension. Starting with the 1960 model year, General Motors completely redesigned their light truck line, and GM engineers came up with a simple, yet revolutionary trailing arm design.

Instead of the frame being supported by the parallel leaf assemblies, a variable rate coil spring mounted between a trailing arm and the frame supported the rear of the vehicle. The trailing arms ran forward and inboard to meet near the center of the truck. This same basic design has been incorporated into many different performance applications over the years, from NASCAR to desert racing. It is a simple, yet effective design that provides a comfortable ride, hauling capacity, and traction.

General Motors decided to build the Chevrolet line using the coils as the standard rear suspension. But, the uncertainty of just how popular the new suspension would be caused them to build the GMC line using the proven rear leaf design. A Chevy though, could be ordered with leafs, and a GMC with coils.

Many classic truck owners want to lower their vehicles, and the trailing arm rear suspension is an easier design to modify than the leaf. The ride height can be changed by simply replacing the coil springs and shocks with drop components available from numerous aftermarket suppliers.

While the leaf suspension can be slightly more difficult to lower, it does offer a more stable ride when hauling heavy or tall loads. GM engineers widened the rear spring width by seven inches overall by mounting the leaf springs on the outside of the frame---instead of underneath each frame rail like the coil setup. This wider mounting arrangement helps stabilize a taller center of gravity, such as a slide-in camper, not really anything most classic truck builders are concerned about. For those with leafs, ECE does offer drop leaf spring assemblies and extended rear shackles.

The trailing arms do have one drawback that needs to be addressed; they are known to corrode between the two stamped halves. Over time, they torque and flex causing the trailing arms to push apart and twist, resulting in failure. To help solve this problem, we now offers a trailing arm rebuild/upgrade kit to allow you to reinforce and strengthen your original trailing arms before it's too late.

For those truck owners with excessive horsepower (is there such a thing?), this is also a great upgrade to strengthen the rear suspension and help put that extra power to the ground.

We'll start by showing a few of the differences between the leaf spring and the trailing arm frames and a few of the key components needed to convert one to the other--- if so desired. One reason to convert to the trailing arms is to run a wider tire in the rear with a mini-tub. Because the leaf springs are placed outside the frame rail, they are just about as wide as the bed floor, but the trailing arms are inside the frame rails, which provide about five inches of extra room.

The build up of Early Classic Enterprises' latest project truck is in full swing, and this month we are following along as Project Heavy Hauler gets new rear sheetmetal. For those who are new to this project, we've been following along as the crew at ECE has taken this well-worn '71 Chevy C20 camper special and installed a new 3/4-to 1/2-ton conversion suspension and rear air spring setup. Along the way, the crew has also cut down the longbed chassis to shortbed dimensions, and installed one of the company's new stainless rear fuel tanks.

This month, we'll cover the assembly and installation of ECE's new reproduction shortbed kit on Project Heavy Hauler.

One of the few drawbacks when building a '60s-era GM truck is the limited amount of choices when it comes to updating the rear axle assembly. Since the majority of these trucks came from the factory with manual transmissions, they usually are found to have a rather deep rear gear ratio.

Now if you're a stop light racer or use your truck to haul or tow heavy loads, then a low gear ratio is generally a good thing. Those of us who like to drive our hotrods at highway speeds desire a higher ratio to lower the engine RPM. This not only saves wear on your engine, but usually results in better fuel mileage.

Many truck owners change the front suspension from the earlier six-lug to the later 70's style five-lug bolt-pattern disc-brake setup, Although there are six-lug front-brake rotors available in the aftermarket, many rodders choose to swap out the rear axle assembly to a later five-lug model.

Starting in 1960 and running until the 1972 model year, GM utilized a trailing arm/coil spring rear suspension design on the Chevrolet trucks, and a rear leaf spring arrangement on the GMC models. Either brand could be special ordered from the factory with the opposite suspension, which explains why you'll see a Chevy with rear leafs and a GMC with rear coils.

For those truck owners with rear coil suspension, it's possible to install virtually any rear axle assembly under your truck by changing the mounting saddles. The pre-'70 rearends 1 1/2 inches narrower than the later '70-87 units.

But as long as a rearend with 3-inch axle tubes (take a look at Ford 9-inch as well) is used, it can be swapped in without much hassle. A new bolt pattern will require new wheels so a change in track width is not a problem as it can be made up in wheel offset.

Replacement axle saddles are available from Early Classic Enterprises that can be welded to a donor rearend at the correct angle and position. The only other dilemma has been the lack of a mounting provision for a panhard bar on the replacement housing. Early Classic solves this problem with our Super Track Bar kit, which replaces the original panhard bar design.

Our kit is designed to mount in the original driver's side frame bracket, but instead of the opposite end attaching to the axle housing, it runs all the way over to the passenger side trailing arm. Their 12-inch longer bar design reduces the radial arc, which lessens the side to side movement of the rearend as the suspension moves up and down.

Follow along as we show the installation of a later model rearend into a '70 Suburban, along with an ECE 5-inch rear drop kit to change from the original six-lug to newer five-lug bolt pattern wheels.

With the popularity and prices of '67-'72 GM trucks currently going through the roof, it's nearly impossible to find a good, clean shortbed truck to restore. Anyone lucky enough to own one has a dozen stories of enthusiasts trying to buy their ride. These popular trucks usually produce a few windshield notes and business cards left by prospective buyers as well.

ple supply of longbed models floating around, and many savvy hot rodders are building the truck of their dreams by acquiring a longbed and shortening the chassis. Now this seems like a giant undertaking, but truck frames are shortened and lengthened everyday to accommodate different applications in the big truck industry. The same techniques can be applied to the light truck market with great results.

Loyal readers have been following along as Early Classic Enterprises has converted a 1971 C-20 ¾-ton truck using their new C-10 conversion spindles and rear air- suspension kit. Now with the suspension finished, it's time to shorten the frame and make this longbed truck about 20 inches shorter than the factory made it.

Over the last few issues, we have showcased the installation of Early Classic Enterprises' new C-20 to C-10 conversion spindles and front drop kit. In the Dec. '02 issue, a C-10 rear axle was overhauled and made ready for air suspension.

This month we will show the installation of Early Classic Enterprises' rear air suspension kit and new wheel and tire combination. The Camper Special turned street cruiser will soon be ready to hit the pavement again. And we hope to continue with coverage of the modifications that will give this sedate truck a much more spirited personality. We hope some of these installation tips will help you when it comes time to get your own projects rolling for plenty of fun-time cruisin'.

Taking The Sway Away

 

Here is the complete Early Classic front sway bar kit. The heart of the package is the powder-coated 1 1/4-inch sway bar, a complete set of polygraphite bushings and mounting straps, the frame mount brackets and all necessary hardware to install.

Carving corners and taking twisties aren't the first thoughts that come to mind when thinking about most early truck handling characteristics, but that doesn't have to be the case. Let's face it, every Classic truck owner wants the maximum enjoyment level and driving performance out of their vehicle. We go to great lengths to update our suspension and braking systems, but sometimes overlook the obvious smaller details than can really make a big difference.
One of the easiest and least expensive handling upgrades is a front sway bar kit, and Early Classic Enterprises offers a stout design for 1963-'72 Chevy and GMC trucks. Designed to help eliminate the side to side body roll, their kit is a simple bolt on affair, with only a drill and simple hand tools required for installation.

Follow along as we show you how easy this upgrade is done on a 1966 C-10 truck.

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