In a message dated 98-05-24 03:34:34 EDT, pleolkes@arcom.com.au writes:

<< I have just purchased some 3 pronged supressed Bosch plugs (part no.
 W7RDTC) and put them in my '89 VAnagon engine. On turning the engine on
 I heard a loud mettalic sound and became immediately concerned that the
 the extra few millimetres that the plug protrudes into the combustion
 chamber was too much and the electrode was coming in contact with the
 piston. I turned the engine off and put my old plugs back in. I am not
 sure what to do at this point.
 I guess I am looking for some reassurance that the extra reach will not
 make any difference. I realize that the thread length is the same and
 the extra reach into the chamber is due to the larger size of the
 electrode compared to the single pronged plug.
 Could you please reply to my address and confirm that you have used
 these plugs with no problems.
 Thanks
 Peter Leolkes
 Adelaide
 South Australia

 Modl6971 wrote:
 >  >>
Peter, I have been putting the BOSCH W7DTC ( three prong) plugs in Vanagons
for 10 years now without ever experiencing what you have just mentioned. Do
your spark plugs show any signs of damage, such as a piston coming in contact
with the spark plug?  Let me know.
 Michael M. 87 syncro.  ( Running on three prong plugs, the only plugs I would
use)
 Also, the part number that you are including says W7RDTC, it should be W7DTC.