I have limited it down to BMW E30 M3 lash pads or 240 Volvo lash pads (valve shims).

BMWs have a slightly convex top on the shim, to aid in spinning, but the camshaft is slightly concave so I hear on
www.bimmerforums.com

My brother got a digital camera for christmas so I am going to take a picture of my heads so you can see what I am talking about.

EDIT: my pictures are too big to attach. I can email them to you MB DOC.

__________________
Current Stable:
1994 S500 v140, 210k miles, white with grey.

Former Mercedes in the Stable:
1983 300CD Turbo diesel 515k mi sold (rumor has it, that it has 750k miles on it now)
1984 300CD Turbo Diesel 150 k mi sold
1982 300D Turbo Diesel 225 sold
1987 300D Turbo Diesel 255k mi sold
1988 300 CE AMG Hammer 15k mi sold
1986 "300E" Amg Hammer 88k mi sold (it was really a 200, not even an E (124.020)
1992 500E 156k mi sold
etc.