1973-1987 GMC Suspension Buildup
No system on your truck affects your driving enjoyment more than the suspension. You may have a 500hp big-block under the hood that can roast the hides, but if the suspension is loose and unresponsive, the truck is going to be miserable to drive. On the other hand, if it handles like a slot car, you can have an anemic six under the hood and still have a blast tearing through some twisties with your foot on the floor.
When it was time to freshen the suspension on our '77 GMC 1/2-ton shortbed, we decided to set it a little closer to the ground and tighten it up with polyurethane bushings. Our truck had a GVW of 10,000 pounds, so it rode a little firm and sat kind of high. We decided to go with a 4/6 drop and contacted Choo Choo Customs for a flip kit. We used a C-notch from Belltech in the rear and 2-inch-dropped spindles, and 2-inch-dropped coils from Early Classic Enterprises (ECE) took care of the front.
To ensure we'd get the kind of handling we wanted, we turned to the experts at Performance Suspension Components (PSC) for a complete rebuild kit, including graphite-impregnated polyurethane bushings and a set of KYB gas shocks. For the steering box, we turned (pun intended) to the knowledgeable people at AGR. They rebuild and customize a wide variety of boxes--everything from stock replacements to ultraquick 12:1 boxes. We opted for one of the company's variable-ratio sport-valved boxes.
We set a weekend aside, and with the help of a few friends, we soon had the truck torn down and back on its way to road-warrior status.
