Strut insert length question (Bilstein Part number confusion)
 

I've read for hours, and I can't seem to find the easy answer to how interchangeable the Bilstein inserts are from year to year.

Lets not talk about damping rates quite yet, I want to know first off if Bilstein insert X can fit into Porsche 911 body Y.

Here's what Ive found out, that merely confuses me. Bilstein lists four different insert part numbers for use in 911's from 1968 through 1989. One of these part numbers (F4-P36-0115-H0)is said to fit 68-89 inclusively, implying that all Boge and Bilstein inserts are physically interchangeable.
While another part number (F4-P36-0112-H0) is listed to fit 1968 only through 1985. and lists it as "B6 Heavy Duty (HD) "

Combining the both above facts, and the difference between them would seem to be only damping rates. Implying the F4-P36-0112-H0 is not suitable to dampen my 1987 because of it's hefty weight.

Thoughts so far? Has anyone measured a bunch of strut insert lengths?

SmileWavy

Next:
IF you look up my 876 911 to find out what inserts it needs, it calls out the F4-P36-0115-H0 as "B8 Sport (SP)". and F4-P36-0114-H0 Setting: B6 Heavy Duty (HD)

I own a set of earlier 911 inserts F4-P36-0112-H0, and Bilstein says that they can re-valve them to be the same damping as F4-P36-0115-H0. Bilstein also says the max and min lengths of both inserts are the same. I just need to make sure that it's going to give me what I want.

Here's my worry: Bilstein describes the F4-P36-0115-H0 as" specifically suited for use with special lowering springs in combination with anti-sway bars or other suspension upgrades."
And I've heard that sport inserts lower the car by 1/2 inch compared to the HD heights.

Which makes me think that maybe there's something I'm not considering that would make a revalved F4-P36-0112-H0 make my 87 ride too high.

Suspension is stock, lowered to Euro height on my 911, with stock 24 year old struts and shocks soon to be replaced.

Thanks,
Richard

You can always adjust the ride height post installation with the adjuster screws.

Or is that too simple an answer? Call Paragon or Elephant.

Adjuster screws for height change were a given. That's how I got my height to Euro height.
I just don't want "old" body inserts making my 1987 jacked up like a off road pickup.

The pressure difference in the shocks won't hugely affect your ride height, unless perhaps you're switching from an unpressurized shock to a pressurized item.

If you were to lower your car even further, below euro height, the valving inside the shocks would not be operating within it's ideal range. This is what the special shocks are adjusted for.

One difference you may not be aware of is that the Boge struts did change in '85. I believe the difference is with the nut that secures the strut insert to the housing, but I am not 100% positive. I didn't double check all of the part numbers you've listed, but this might explain the extra sets you're seeing.