TSB 18-023-06 Dated July 14, 2006
I quote.
"Flash Enhanced Torque Converter, Glow Plug, SKIM and Throttle Valve Shutdown operation Or (but I think it means AND)
Brake Switch DTC 504"This one superceeds 18-00806 and 18-009-06.
I think this one has a early version of F37 and reduced the torque and changed the shifting. Under
"Overview" it says:
"This bulletin involves selectivly erasing and reprogramming The Engine Control Module (ECM) and Transmission Control Module (TCM) with new software".F37 instructions say that it (f37) superceeds TSB 18-023-06
I don't know if you want this one or not

I wonder what if any good TSB's are included in GDE's tune??
That's a really good idea. GDE's tuning may be able to accomplish what you need without doing the F37.