I came across some literature, http://durranceeng.com/
that said that I should not have been running WR9DC plugs but should be running W9DC plugs. Lose the R(esistor). http://durranceeng.com/even_more.htm
The MB plug wires already have the necessary "setup" to fight radio noise.
So we'll see over the next few years what happens.
S, J.R. Brown
2000 G500 LWB Obsedian Black
2005 Toyota Tacoma Access Cab Off Road Sport
1993 Volvo 240 Sedan Anthracite
1980 450SEL Champange (owned it for 15 years. Great car)
1986 280GE LWB Anthracite (Sold it and kinda wish I hadn't)