With the exception of when appearance is an issue—using a steering box on a traditional rod, for example—the use of a steering box or rack-and-pinion is down to personal choice when there's an option of using either. And when it comes to Tri-Five Chevys, there's definitely a choice. More than one manufacturer offers new steering boxes for these cars, and in fact that is what was removed to fit the Unisteer rack-and-pinion, as the owner of this blown big-block–equipped 1955 wanted the responsiveness and just over two-and-a-half turns lock-to-lock that the rack-and-pinion offers.
Installing the kit is actually very simple, a bolt-in deal. What takes the time is hooking the rack-and-pinion to the steering column, and removing the original steering assembly. This car had no original steering column or steering box to disassemble. On a stocker the inner column shaft is part of the steering box, and is removed from the car as a single unit. As mentioned, this particular car already had an aftermarket steering box installed, making removal simpler.
Unisteer offers its Tri-Five rack-and-pinion kit in either manual or power options, and in black or chrome. All are designed to fit a Tri-Five with a small-block Chevy engine, though an LT1-specific kit is also offered. All will fit cars equipped with dropped spindles. The installation we're following at Jimenez Bros. Customs (JBC) is on a big-block–equipped 1955. The main difference is routing the steering shafts, as the physical size of the big-block and its headers makes things awkward. The actual rack-and-pinion kit fit with no clearance issues.
Unisteer actually offers a shorty header, made by Sanderson, to complement its kits, as well as a Tri-Five steering shaft kit, comprising two universal joints and one intermediate shaft. Also available is a bushing to convert stock, non-shift steering columns for use with the rack-and-pinion kit. JBC fabricated a steering system using two intermediate shafts and a support bearing in order to clear the big-block's headers. Another option, as an aftermarket steering column with a 1-inch DD hollow shaft was used, would have been to insert a length of 3/4-inch DD shaft into the column shaft, and pin or bolt it in place. This would have eliminated the support bearing. With the weight of a blown big-block and manual steering, however, the option JBC chose is stronger and safer.