What is the ride difference between the regular Bilstein and the HD and Sports Bilsteins. I have an '87 300E, and am contmplating keeping the original springs, but installing 420E antisway bars front and rear and 205/60/15 michelins on the stock rims. I would like a little firmer ride, would the HD or the Sports bilsteins be better with the stock springs. (Bilstein implies that the Sports struts are for use with shorter spring kits) I don't want to pound my kidneys loose, but would like less roll and a slightly firmer ride and handling.

Also, is a tuner chip available for this engine (M103)?

Thanks for all the great info from this site!