EUREKA!!!! Finally found the blasted vacuum leak that had been plaguing my veritable sanity! The PO concocted this crazy brass block setup at the rear of the carburetor, which I attempted to just go ahead and replace with all new pieces, just match them and replace. NOT so easy. After going to 5 different auto parts stores, Lowes, and 2 alternate hardware places, no one could even come close to what was there. ( 2 of the auto parts stores told me that most of their brass fittings were being removed, as smokers of illicit drugs were using them to make smoking apparatuses!- One place even had the audacity to try to ID me when I purchased a fitting! I told them to cram it, and give me the part-which they did!). ANYway, after 15 solid months of spending 8-18 hours a day out in the garage, it actually feels like I'm making progress. (I might have had 30 days off total in that time) One of the brass blocks had a hairline fracture in it- NOT really noticeable, looked like a casting mark. Spraying it with carb cleaner made no rpm change at all. Pulled all that garbage off the back, installed a threaded barb, connected the booster line to that and cranked it up- WHAT A DIFFERENCE! It now idles smooth in gear!!!! Now BOTH idle mixture screws actually function! All I have to do now is connect the vacuum modulator line up. (NOT to the rear again- hopefully it will function properly connected to the front port on the drivers' side of carburetor. I also moved the advance line to the right side timed port-she likes that spot!). I had to take a few steps back and a few deep breaths and start fresh. THANKS TO ALL who helped me through this grueling process. My confidence level has finally risen, at least to the surface! THANKS!!!!