E36 Bilstein question

[robbo86]

Ok, I will try and keep this as brief as possible.

I have an e36 328 which was formerly my old mans. When my old man had it he bought Bilstein shocks and Eibach lowering springs for it after recommendation from a friend (who supposedly should know, being a steering and suspension specialist for McClaren). By the 2009 MOT both rear shockers had failed (car had probably only done about 3k miles. They were replaced under warranty. 2010 MOT and the rear passenger side shock has an advisory which my dad does nothing about. Car then passes to me and by the 2011 MOT car has failed because of a shagged out rear shock. In this time the car has probably done a maximum of 9-10k since the original kit was fitted and none on a track. Getting annoyed with this I sent an arsey email to Bilstein who forwarded it onto the man who deals with all their imports, an employee of ECP. Bloke is very helpful and says to tell the supplier to replace both at the rear under warranty again (despite being just outside it) and sends me a part number to check I have the right shocks. The number he sends me is not the one on the invoices and I tell him so, asking if it's the part number for b6s which I believe I have fitted. He tells me

"Was it B6 you purchased then ? this was the B8 number and are meant to used with lowering springs"

I replied that I was sure I read that b6 can be used with up to a 30mm drop, but can't remember where (I think it was the Bilstein website) and this is what drop the eibach lowering kit was.

I was of the impression that b6 was best compromise for not too crashy a ride as the b8s were really hard, but thats by the by as it's just what I thought and had no bearing on what my old man may have chosen to buy. Anyway my points are as follows:

Is the use of the eibach lowering springs likely to cause the failure of the b6 shocks (assuming that they are)
Do I (or my old man) have any recourse as the website of the suppliers does not state that b8s over b6s should be used with lowering springs? Similarly when filling my dad in about this he stated that the original shocks were bought packed and delivered at the same time as the eibach springs and to the same person, by that token, they are hardly likely to be for a separate application. Again this is very true.

Basically I dont want to have to replace all four shocks with brand new B8s if I don't have to, if the b6s are going to do fine. On the other hand am I going to spend more in the long run if they keep failing because they are not designed for a lowering.

[robbo86]

Found it, taken from the suppliers website (which was Motorsport world)

"Bilstein B8 shocks are shortened versions of their B6 shocks and are aimed at applications where lowering springs of more than 30mm are to be used."

That to me says b6 can be used with lowering springs up to 30mm

[robbo86]

No one?