I picked up their 899001 kit, this basically has an assortment of washers you can use to adjust the output pressure in your power steering pump.

Curious if anyone can provide some direct feedback on their experience with this mod?

Here is a quick copy/paste from their insturctions (attached to the post for reference) which indicates the impact the number of shims used have on output pressure:

Pressure Chart
The Following Chart is for reference only different pumps may vary pressures.

Mustang Rack and Pinions generally require Approx 1000 PSI.

No Shims - 1350PSI
1 Shim - 1200PSI
2 Shims - 11OOPSI
3 Shims - 1000PSI
4 Shims - 850PSI
5 Shims - 700PSI

Meanwhile, the Mopar FSM for my '80 coupe only states the following regarding maximum pressures:

225 Engine with A/C 1000-1100 PSI
All Engines Except 225 With A/C 1200-1300 PSI

Thanks!

I'd call Borgeson & ask them if you should duplicate the shop manual psi spec & if you want to achieve the max listed or be under that & if so what %

Yes, absolutely, hoping to get a few minutes at work tomorrow to ring them up.

In the meantime, was really hoping to get some hands-on feedback here regarding the resulting "feel" a particualr final pressure had.

I realize this is a very subjective assessment, but at the very least it is a starting point.

In Rick Ehrenberg's article he adjusted the p/s pump pressure down to 800 psi.

http://www.moparaction.com/Tech/beep/PUMP_IT_DOWN-re-v1.4.pdf

The max pressure of the rack is 1,000 psi. That means you want to be under the 1,000 psi mark if possible. That means, to me, you want to add 4 shims for that 850 psi. Its not that hard to add or remove a shim, but I would start at the lower pressure.

If the pressure is too low, the steering will feel like the power steering is not functioning correctly and will take a bit more effort to steer the car. Higher engine rpm will probably improve the power steering feel. If the pressure is too low, remove a shim.

Too much pressure makes the steering quirky and over reactive. The higher rpm the motor is turning, the worse it becomes. That means the steering may be OK in town, but will have you on edge at highway speeds. Gene

good info & me I'd want it a bit less cuz as we know Mopar assist dont leave much feel

Guys!

Alright...some first hand experience to report!!!

So...baseline first, I took my ham-can (Saginaw) pump apart and found only 2 shims for a total thickness of 0.037". The Borgeson kit has 6 shims that are 0.020" thick each...so given the Mopar Action article on this subject which stated that the /6 pump they tested read about 750-850 psi I thought I'd take the plunge and go for 5 shims totalling 0.100". This would get me to the advertised 700psi output which is almost a 50% pressure reduction.

No sweat, got the stuff installed. The kit included sleeve to hold the valve stationary as you install the washers, a great tool.

Drum-roll pleaaaaassseeeee....I took the car for a drive. At idle the steering is a bit harder, you can tell it is no longer the over-assisted feel. But actually a welcome change, so no complaints there.

Next came the road test...I wasn't quite sure what to expect, so I took it slow and easy...at first...LOL...because you quickly fall in love with the improved feel. Granted, my steering gear was already in a good enough shape with very minimal slop, so I had a good starting point. Now with this shim install I kid you not when I say it actually made the car nearly modern-day civilized...to the point where I have to remind myself that while the steering wheel "feel" is great my ride is still a 3600lbs vehicle which can't quite handle the rapid adjustments the new feel sort of encourages you to take!!!

Soo...if you are thinking of doing this...by all means, take a stab at it, I think you'll be pleased!

Thanks for sharing your results. I have planned on doing this for a while but I'm a hopeless procrastinator.