408 Idle surge in gear

[fossil39]

I have a 2002 GMC truck with idle surge in gear, and just barely in park at times? Mods as follows:
-408 Lunati stroker, L92 heads, L76 intake, CR 10.2:1, 232/238 .599/.601 camshaft, 255lph fuel pump with adjustable regulator, 3500 stall, Beefed up 4l65E, 9.5" 14 bolt 4.10 rear end.
Any help would be greatly appricated.

[7420NW7TH]

With that size cam your o2 sensors may be reading lean (falsely) and therefore the PCM is adding more fuel. Idle surging often (not always) is do to too much fuel. I noticed from your tune your running closed loop. Force your tune into open loop mode and see what happens. Keep a close eye on your o2 voltages and your wideband (if you have one). Also pull the plugs out from time to time and take a look (while you are running open loop) to make sure you are not running too lean. Thats what I would do.

[fossil39]

Question, why run in open loop all the time? To run off ve table to have more control of fuel delivery?