Hi thanks for the links and the suggestions. I do have some experience with carbs, I've rebuilt a few, adjusted more and replaced my 401 carb and manifold myself. The car was originally purchased in Denver (I got that off of the ID plate), so maybe it has high altitude jets in it. I'm a little confused by the fast idle adjustments, and like I said, screwing the idle mixture screw in our out doesn't seem to have an effect. On my other older cars, screwing in the idle mixture screw would generally richen the mixture, screwing it out would lean it. Usually the effect in one half turn was really noticeable. I'll give it a try again tomorrow. I hate all the pollution crap on the car, but in my opinion the cast iron manifold has it's advantages. I had to go through a lot of hoops to prevent vapor lock when I installed my performer manifold and carb on my 401 V8, that aluminum manifold and carb acted like a big heat sink drawing the heat off of the head.

thanks,
chuck