I installed a set of hedman headers on my 82 CFI Z28 and now my idles hunts for awhile after started cold and when I am driving it, it has a good sized stumble under load off idle. If I pull out from a stop sign it will go fine for about 10 feet, stumble then take off. All of the vacuum lines are reattached except for the smog stuff since I took all that out. That port is plugged. I figured it would act funny when it went to open loop since I still need to have a o2 bung cut and welded in but it does it no matter if its in open or closed loop.

Please help me solve this.