Those AFR #s just seem way off. It doesn't seem that the SU's are a good match for that engine combo. Idling around the 10's would foul plugs pretty quick I think. And then to go lean at the upper end is quite a swing. I run around mid 12's at idle and 15's at cruise and 12.5 at WOT. I don't have a real answer for your idel situation, but I know any hangs up in linkage can be a PITA-as stated earlier.

I'd have to agree with you that SU's with SM needles are not a great match for my engine. That's the reason I switched to Mikuni's for my track car build and I am in the process of moving my 73 daily driver back closer to stock. For clarification my idle is in the 10's in the texas heat with no heat shield extension. With the heat shield or in the winter I get closer to 11.5 at idle, 12's at WOT and 15's at cruise. I'm still fat at idle compared to your number but it runs fine idling in the mid 11's.

The so called idle control valve is not an idle control valve in the sense that it controls idle speed. What it does is help control emissions on the over run by letting the throttle valves stay open for a periond of time preventing a rich condition when you take your foot off the gas.

I left the stock heat shield in place and drilled three small holes along the edge of it. I then poked holes in the heat blanket and zip tied it to the stock heat shield on one side and to the brake lines etc on the inner fender on the other side. I never meant this to be a permanent installation but more of a proof of concept. It held together without moving for 8 track sessions on a NASCAR oval and several weeks of daily driving. The heat blanket I am using has a finished edge. This most likely helps it to hold a zip tie better. I will eventually get around to building a more permanent, better looking heat shield but for now this one seems to be working great.

Thanks!

I puttered around for a couple of weeks at higher altitudes after asking about the installation and checking back slipped my mind. Thanks again, I got a visualization on what you did.

Chris