I spent serious time today adpating a new return spring and assembling new throttleshaft seals for these HIFs. The end result is a car that runs and idles at it lowest at around 900-1000 RPMs. Just low enough to get my timing adjusted back to spec (10 BTDC). Idle gets higher as the car warms up, regardless of how I adjust it. Maybe I should used soime phenolic spacers. I have one. Does someone have one or two they like to part with?

On the plus side, the deiseling is almost gone.

I also spent some time servicing my older three-bolt HS6s. I quit using them because the throttle shafts were pretty loose and the car ran poorly. Plus, I figured with a B20, I shoudl use the HIFs. However, I salvaged a much nicer pair of shafts from my "junked" two-bolt HS6s and replaced them over-worn shafts. I think the HS6s will probably perform much better now.

I know that HS6s can be run on B20s. Can anyone give me a sense of the performance and economy of such a setup?