I don't know,... my BLM's are all between 127-129 and the car runs smooth. I've only used a wide band for WOT tuning, but hey.... I'm new to this so... I can only offer my experiences and what I...

I am by no means an expert HOWEVER I do have a 1990 Corvette I am working on that had some of the same issues. I am in the process right now of tuning it as well so we may be able to help each...