The only thing worse than not having a taut-handling car is not being able to take full advantage of everything a great suspension promises because of an ancient, slow manual steering gear box. That was Shannon Hudson's dilemma. You may remember his lime-green 1969 Plymouth Valiant from a previous story ("Plymouth Valiant - Total Handling Transformation," July '10), where we detailed its Hotchkis-bred suspension upgrade. The improvements included shocks, torsion bars, leaf springs, sway bars, tubular front upper control arms, and tires and wheels.
All these pieces put this little Plymouth Valiant A-body on its way to a fun-loving life of canyon-carving—at least, that's what Shannon thought. But hampering that enthusiasm was a wretchedly slow manual steering gear box that was far better suited to drag racing than any sort of apex-carving performance work, especially when it came to the autocross. "It was just really slow," Shannon says.
Normally, a power steering gear box upgrade would be simple a bolt-in deal, but Shannon had also added a Vortec centrifugal supercharger, which created subtle problems. "I asked around," Shannon says, "and everybody said my power steering gear box upgrade couldn't be done." The big hurdle was the oversized factory steering gear box, and no one made a power-steering-pump crank pulley. But solutions come to those who persist. Shannon learned that Borgeson, the high-performance steering specialists, had adapted Mopar mounting lugs to a petite import power steering gear box that would bolt directly to Shannon's Plymouth Valiant and any A-, B-, C-, or E-body Mopar. The box also uses the same Pitman shaft diameter as the original Mopar box, so the factory Mopar Pitman arm can be reused. One big advantage for this new steering gear box is that its smaller size also creates an opportunity for swapping in a late-model Hemi engine, something Shannon is considering. With all these benefits, the technical moon and stars all appeared to align to make this conversion. The new power steering gear box twists a much quicker 14:1 ratio, offering far superior feedback to the old, one-finger '60s boxes, and it's leagues quicker than the manual steering gear box. Check out how Shannon made this system work to his advantage without resorting to an expensive custom K-member and rack and pinion.
Parts Box
Description
PN
Source
Price
Borgeson Power Steering gear box
80118
Borgeson Steering
$749.00
Borgeson Universal joint
036425
Borgeson Steering
130.00
Borgeson Steering adapters
95120
Borgeson Steering
26.00
KRC P.S. pump
50010000
KRC Steering
228.95
KRC P.S. bracket
31515000
KRC Steering
68.47
Zoops crank pulley
Custom
Zoops
Call for a price
Ididit steering column
Custom
Ididit
Call for a price
Grant GT wheel
1770
Summit Racing
117.99
Bleeding the System
With a new steering gear box and pump, there is one remaining step to complete before the first test drive. With the pressure and return hoses installed, fill the system with quality power-steering fluid and raise both front tires off the ground. Slowly rotate the steering through its entire sweep lock to lock while watching the fluid in the reservoir. You should see bubbles in the fluid, which is air displaced by fluid. Maintain the proper fluid level and continue to rotate the steering until the bubbles no longer appear. Now start the engine and check for leaks.
The first hurdle to clear involved mounting the power-steering pump on the driver side to work alongside the Vortech centrifugal supercharger that Shannon had recently been installed.
In addition to the Borgeson Steering conversion box...
...the company also suggested including an ididit steering column that could be easily adapted to the Borgeson steering box with a single universal joint.
Other necessary conversion parts included a KRC pump, pulley, and mounting bracket.
This photo shows how tight the stock manual box is in the car. Stock Mopar power-steering boxes are larger, which was a major reason for the Borgeson conversion box since Shannon eventually wants to install a late-model Hemi.
The KRC cast-iron pump is actually a GM Type II pump modified with a -6 outlet fitting and an integral aluminum reservoir. As you can see, there’s plenty of room around the pump to allow the integrated reservoir. What made this work was a custom Zoops crank pulley that was sized at 5 inches to underdrive the pump’s 6-inch-diameter pulley.
With the new Borgeson box in the car, note how much more room there is. At the same time, Shannon removed the headers, which also increased the clearance.
The Borgeson box requires metric/AN adapter fittings, which Borgeson also offers. The high-pressure side (arrow) is the 14mm input thread, while the larger 16mm fitting is for the return side. Hudson had his local NAPA store build custom hoses for the application using Aeroquip steel fittings. If you choose to use aftermarket hose, KRC recommends Aeroquip QRP hose even on the return side to prevent collapsing the hose during high-demand situations that could starve the pump. The pressure-side hose should be capable of withstanding 2,250 psi.
Borgeson offers detailed instructions on how to modify the stock steering column to adapt it to the new steering box, but Shannon opted for a new ididit steering column that was custom-sized for his A-body application. This also required the use of a Borgeson Universal joint connector that adapts the splined input shaft with the D-shaped column.
With the column in the car, Shannon chose a smaller-diameter Grant GT steering wheel to complement the quicker steering box. Installed in the car, the column and wheel work well with the Redline Gauge Works–customized Auto Meter gauge package Shannon installed in the dash.
This is the engine compartment now complete with the Vortech supercharger and the power steering. Now that Shannon has the power and the quick steering to match his Hotchkis suspension, the next conversion may well be to a strong overdrive manual transmission.
For now, Shannon is just out enjoying his newfound quick steering response and agility on the autocross track.
