Thanks for the plug, Shawn. I don't get out to the bulletin boards much anymore these days -- apologies to anyone who might care.

I'm certainly not discouraging people from using headers, BTW, it's just that there are more cost-effective things to do first.

I don't know of a source of SU needle listings on the web. There are something over 800 needles available, and the two-letter codes are apparently random. On stock or near stock Volvo motors equipped with HS6 carbs, the following three are standard and well-matched (in order, from lean to rich):

ZH = B18D ("A" or "B" cam standard, depending on year and tranny type)

SM = B20B ("A" or "B" cam standard, depending on tranny type)

KD = B18B ("C" cam standard, high compression)

The KD needles also work very well in B20E or F motors still using their native "D" or "K" cams, but converted to HS6 carbs.

On the other subject, yes, that's just exactly a Panhard rod on the rear axle, and its function is to locate the axle laterally. It's theoretically a source of bump steer but practically works just fine.

--Phil