Stroker engine "diesels" after I shut it down

Really appreciate all the expert ideas here guys! My carb is on a 1" blended phenolic spacer, new gaskets and I do not think anything is warped. This all started after I adjusted the idle up using the primaries so that is where I will start the investigation. Wish my MSD 6AL had start retard though. Lately I have been cranking the engine over with the ignition off to get oil pressure going before it fires as when the engine is cold I have to bring it up to 2000 or so to keep it running until it builds heat. I will also get in the habit of killing the engine in gear with the brake on.

I bought the engine here from a man who had it built 3 years ago and it sat all that time after the dyno runs. I had pulled the heads and took them in to get the valve spring pressures checked. Did not see any spots that could cause hot spots, the heads were pretty nicely prepped and everything was carbon free.

All I know is the dieseling is bad juju not to mention embarassing - just not cool sounding. I even added a little 110 (50%) to the 93 I run and it didn't seem to help so there is something else going on.

And OMM, the X pipe stays. I can't argue with picking up a 10th after adding the X pipe and flowmaster 40's with the associated weight gain. The car sounds pretty good to me inside the un-insulated body but I am told by observers it is a tad loud when stomping it on the street so the 14" x 3" resonators will go on and the ET will determine how it affected the performance. Already bad enough cop bait as the car is still basically a track car with a tag.