Can you make two recordings. One with sputtering and one without. Then lets compare both.
Wonder if the engine moving around could be an issue. As if you roll into it there is no problem.
I have seen stupid stuff like loose connections on the starter cuasing issue with the fusible links, I have seen the loom that wraps around the drivers valvecover rub on the transmission neutral safety arm and short out the 12v line. I mention this becuase I see you have aftermarket valve covers.
i have to wait till full throttle sends me my powerlogger. as for the roll in no problem. i can only do it in third if i try in second or first it still does it. i will try to look at the wires and see if any thing is loose