Rick,

Like many other things tyre technology has moved on in leaps and bounds and tyre rigidity design is doubtless much better understood due to finite element analysis calculations that help engineers fine tune the design. I was probably able to get away with 24 psig on the Michelin Cup tyres I ran with briefly due to their immensely strong designed for racing sidewalls and of course the additional width. As I am concerned the best thing owners can do with the RDK system is by pass it using the "jumper in the plug" approach to fool the system into believing "all is well". I was never sure what that system was meant to achieve that a sensible driver can easily achieve. Not sure I would want to know my tyre is screwed whilst travelling at speed! Before setting off on a drive I always take a squint at all the rubber to ensure there are no visual side wall bulges due to low pressure and physically check the pressures with a quality analogue pressure gauge every two weeks. If it gives some drivers a sense of security all well and good of course.

 

Here's something to take the guess-work out:

https://tiresize.com/pressure-calculator/

As for me, after much experimentation, for these sizes:

265 x 18
295 x 18

...I'm running 33 psi front and rear.

I started at 31 psi because that's what the Corvettes are running with similar sized tires, but that was too squishy.

Next, I jumped to 35, but that was too jarring, then I went to 33 and it was the sweet spot for me, and the tires are wearing perfectly.

 

Ok, I have the bushings enroute from Delaware Porsche and have finally removed the driver’s side upper control arm. Would have been a simple task if there had been a smidge more clearance between the control arm and the coil spring but I ended up having to remove the spring and shock assembly to get the arm out. Luckily, the long pin was not that difficult to remove and still had plenty of grease on it.

The problem is that the bushings in the control arm appear to be in excellent shape (see pictures) so either they are somehow worse than they look or I just needed an alignment. Perhaps the passenger side is worse, we’ll see. Is there some trick to getting the arms out without removing the shock?

Otherwise, I confirmed that the shocks are the original Boge Reds (928 333 051 17) which I have to decide if I am going to bite the bullet and pay $600+ apiece to replace. And sentiment seems to be that the bushings that the pin passes through aren’t worth the effort to change as they seem to wear well and the difficulty of replacement is high. That leaves the rocker bar bushings and the ones in the upper cross member.

 

to remove the dog bones you have to remove the shock strut assembly.
Those bushings look original in the dog bones.
make sure you properly Id the location of the upper control arms,
as the if they go in back wards they will rub on the upper cross member mounting point.

 

Thanks for the guidance Mrmerlin, much appreciated. Without this forum and all who contribute, there would be a lot more of these fine machines sitting or running poorly.