surges after running for awhile

so I just got my basically stock 318 upgraded with a dual plane edelbrock performer intake and 1406 carb. I'm having a problem that after driving and stopping the car surges a like every second or so for about 20 seconds before settling down. The rpms will increase by about 400 rpms during the serge.

the car runs fairly well beside that but doesnt really sound great, it has a kinda papery sound out the back at idle.

I'm thinking maybe its getting too much fuel and will surge when it ignites the extra fuel. my dwell looks like it could be a bit low, 25, but I did a tune up not long ago...

Any ideas?