I just got an act s/s disc and 9 lb flywheel put in my car. And even before i got the new clutch my car whenever i would press the clutch to take the car out of gear to stop the rpm's would drop way down below 1000 and then bounce back up. sometimes it would drop all the way down and stall the car. i thought it might be the clutch so i replaced (cause i had to) it. it still has this problem. Its not the clutch switch had that checked out when the clutch was done. any ideas would be helpful im taking it back to the place where it was done tomorrow to see if they might know. thanks guys.

 

This sounds like the throttle dashpot is going bad. It’s designed specifically to prevent the problem you describe. See the attachment if you need to identify/locate this part on the engine throttle body. The manual has a good write-up on test/adjustment, but these rarely need any adjustment once initially installed correctly. Can't hurt though.

I suspect the problem was actually made worse with the lighter flywheel because the engine now has less rotational energy to help carry it through its transition to idle speed.