idle questions
Slow down for a second. Suddenly you are heading in two different directions; fix existing set up, or full head and intake modification. Which is it going to be?
All the previous problems will be eliminated if you use new manifolds and carburetors.
If you want to just fix original engine, than get a set of the good gaskets:
http://catalog.remflex.com/category_s/87.htm
Those thick gaskets should seal up your warped manifolds ending any vacuum leaks. I use them on my car.
Engines are just air pumps. The reason the engine runs well at speed is as the rpm increases the amount of air entering via vacuum leak becomes progressively smaller in relation to the total air moving through the engine making it irrelevant. When engine is idling, very low air volume is being pumped, so a vacuum leak will dilute the air fuel mixture enough to cause a too lean condition, and poor idle.
Once you get the combustion chemistry (air fuel ratio) the same for each cylinder, you can than start tuning the carburetor. If you don't you are just wasting time and effort as it will never run right.
Setting lash cold: just add 0.002” to stock setting of 0.010” I & 0.012” E. This will get you real close once engine has warmed up for final adjustment.
Side note where can I get bigger valves from I was pointed to a guy on ebay but he is out.
Funny you should ask, this very question came up on /6 this morning, and a few of the engine gurus chimed in on a work a round:
http://slantsix.org/forum/viewtopic.php?t=49079
Setting float level should have been covered in rebuild instructions. Look here for more carburetor tuning information:
http://www.slantsix.org/forum/viewtopic.php?t=33102