carb is not going to smooth out the idle...

you are going to get a lumpy idle because of the duration of the cam...

best thing is to make sure your timing is correct...and re-curve the distributo to bring in the advance faster..

Tony

70 AARCuda Vitamin C
71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield)
71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas)
71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)