Sorry, I wasn't questioning his or your expertise. I just know that things are different on the street than they are in a dyno cell. I was just trying to help you suss out your minor inconvenience. I'm thinking your idle is a bit much for a stroker with that cam. When I last had my 416 running, it was idling about 750 - 800 with a bigger bumpstick and a Thermoquad.
I'm just suggesting that there might be more tuning needed now that you have changed your backpressure.
