Slant dies when put in gear.

i was just having similar issues with my super six setup. i rebuilt the carb last year and did the swap. it worked great. the last few months it got to the point where it was on and off sometimes it owuld idle like crap then go away. then ;ast week it got to the point where when driving if i let off the gas, it would die. pulled it apart and found some rust sitting in the bottom of the bowl. i hit all passages with brakleen and air and noticed the throttle shaft was a little loose so i peened the edge of the carb base around the shaft to tighten it up. works nice again.