IF, after you CHECK EVERYTHING for vacuum leaks and find none, AND IF you're running a larger than stock cam, and adjusting the metering rod tree doesn't help with surge or idle. Here are a couple items that will fix the problem. First on idle.


Take a numbered set of drill bits and using them as a gauge find the size that fits EXACTLY in the small brass tube in the picture. Drill it .001 to .003 larger. That should do wonders for a thermoquad that won't idle with a larger cam,(richens idle).
IF you have an LM-1 meter the next mod will help you really dial in the lowspeed curcuit.
Pick up some holley bleed blanks and drill and tap lowspeed bleeds. FIRST though use numbered drill set to find out the stock bleed sizes and WRITE them down for reference.
To richen the curcuit up go a couple thousandths SMALLER on the bleed. For the hispeed primary bleed you can also do the same. Hispeed bleed is the other bleed shown in the picture. Dave
After rereading the post and seeing that Demonsizzler did the carb for you, I'd talk to him before doing ANYTHING to your carb. He is the master at modifying thermoquads.
For you other guys that feel adventurous, these mods can be done at home by anyone with a little mechanical ability. I WOULD NOT screw with a numbers matching carb but find another replacement to modify. You don't need to drill holes in the butterflys to get one to idle.