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Tri-Five Suspension - Framing A Classic, Part 4

Moving Up Front With A New Suspension And Improved Steering

Most enthusiasts will agree that updating a vehicle's front end (suspension, brakes and steering) is the most direct way to give an old car more modern handling and road manners. The practice is old hat for many Tri-five enthusiasts, as they've been adapting disc brakes and a simpler form of power steering to their cars for decades. So when it came time to assemble the front suspension on the '55 Chevy chassis in our "Framing a Classic" series, it only made sense that we would take advantage of such tried-and-true updates, while also adding a few newer touches.

Our quest for better handling began with a 605 power steering box from Mike McGaughy's Classic Chevy. Anyone familiar with Tri-fives knows that the 605 conversion, which uses a steering box designed for '78-and-newer GM G-body cars, is one of the most common '55-57 Chevy chassis modifications. The conversion used to involve a fair amount of grinding and the partial disassembly of both the original steering box and the 605 unit, but aftermarket kits like McGaughy's have simplified the swap over the years. McGaughy's 605 steering box comes completely rebuilt (it even includes a new sector shaft) and is designed for simple, bolt-in installation. In other words, it's an easy way to change from manual to power steering. In fact, many enthusiasts prefer 605 steering over factory '55-57 Chevy power steering systems, which were designed with a cumbersome, high-maintenance power cylinder and control valve in the drag link assembly.

Speaking of the drag link, it was one of several used parts we needed to complete our steering system. The other necessary used items were the steering arms, Pitman arm, and idler arm, none of which are available in reproduction form (and since we started out with a bare frame, we had no existing parts to re-use). So we turned to our friends at D&P Classic Chevy (who deal in both new and used parts) to come up with these components. Then we called up Danchuk Manufacturing to order new tie rod ends (both inner and outer) and urethane boots. Danchuk also supplied us with one of its idler arm bearing kits. This nifty kit replaces the idler arm bushings with roller bearings. It's marketed as a way to improve Tri-five manual steering (they call it a "poor man's" power steering), but Danchuk reports that it also works well with 605 conversions, so we decided to give it a try.

With the steering headed in the right direction, it was time to think about the suspension and brakes. For this we turned to Heidt's Hot Rod Shop. Heidt's started off our suspension by supplying us with a pair of 2-inch dropped spindles and 1-inch dropped coil springs. The full 3-inch drop that these parts provide will not only give our chassis (and car) a cool stance (especially combined with McGaughy's lowered leaf springs out back), but should also help our handling situation a little by lowering the vehicle's center of gravity. Heidt's also improved the braking ability of our chassis by providing a complete disc brake kit. The kit uses late-model-style GM calipers and rotors, and came complete with brake pads, bearings and seals, hoses, and other necessary hardware.

While the spindles, springs and brakes were great, we needed control arms to hold everything together. Remember, our chassis started out as a completely bare frame, so we didn't have stock A-arms to work with. And while we could have found some used A-arms to rebuild, powdercoat, and install, our goal with this series is to avoid using OEM parts (just to prove that it can be done). With that in mind, we had Heidt's send out a set of tubular upper and lower A-arms. The tubular arms are not only strong and look great, but the upper ones are built with offset cross-shafts to increase camber adjustability. This helps compensate for upper control arm mounts that have deflected inward over the years, preventing proper alignment. The arms come fully assembled with new bushings and ball joints (since the lower ball joints face down, Heidt's only uses genuine compression-style ball jonts in the lower arms), and are available in bare steel or polished stainless steel. Gary practically insisted that we use the stainless versions, which are a little exotic for this particular build-up, but look great nonetheless.

With all of the major parts on hand, we still had to gather a few components before initiating assembly. One of these was a front sway bar (or anti-sway bar), which we got from Danchuk. The 7/8-inch bar should give our car more stability and support during cornering, keeping it from leaning and plowing so much. The remaining last-minute parts came from C.A.R.S. and included upper A-arm bumpers, a centerlink rebuild kit, and a Pitman arm dust cover.

Like the other portions of our chassis build-up, the crew at Williams Classic Chassis (Larry Garrett, Jesse Howe, Jeff Howe, and Earle Williams) handled the assembly work on our front suspension. As you'll see, the entire procedure was pretty straightforward-almost everything was a bolt-on. But we should remind you that coil springs can be dangerous, so it's always wise to use extra caution (and a quality spring compressor) when installing them.

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