E38 ECU question

I have an offroad buggy that I race. I originally started with a 2007 l92 and a 6l80e out of a Yukon denali, and I bought a E38 ecu that I was told was from a 2007 escalade, and that is what the VIN comes up as. I had this combo dyno tuned several times as I ended up camming it, and putting a higher stall converter in it. The motor ran very strong but the tuning was never right. The shifting of the trans was very unpredictable, and under WOT I would hit the rev limiter, and than have to let off the gas to get it to shift. I eventually set up tap shift and loaded a 2007 corvette TCM tune. The tap shift was better, but it is very slow to respond. It feels like it takes 1 second at least from input until it actually shifts.

OK now fast forward, and I recently put a new motor in it. It is a ls3 block 418, with TFS ported cathedral heads, ported LSXRT intake, Ported LS3 throttle body, 2010 6.2 flex fuel injectors, LLSR cam motions 250/255 cam, 11.7:1 compression with forged bottom end. This motor has been dyno tuned once, and all seemed good on the dyno, but when I got it on the dirt it would spit, and sputter from just after idle until about 4000 RPMs and than it would clean up and pull hard, and than just bounce off the rev limiter. The tuner used my same ECU and OS, and I feel like he made minor changes to the tune from my L92, besides work on the idle, slow down the RPM drop when you let off the gas, changed some injector data (but did not use the actual data because they are 3 bar injectors vs 4 bar, and he pulled some midrange timing because they saw some knock on the dyno. (Replace plus and wires since than, I possible had a questionable wire even though they ohmed well).

I recently started talking to another tuner about my problems and he recommended getting a 2009 corvette ECU, and building my tune off that, and flashing my TCM with a 2009 corvette tune. He also recommended changing my MAF from a CTSv MAF to a LS3/LS7 MAF.

Now for the questions do you guys feel like getting the different ECU will make the tuning process work better with my current motor?

Will the 2009 ECU play nicely with my 2007 TCM?

I know they changed the TCM in 2012 in the corvettes and ZR1s, should I swap one of those TCMs in to speed up tap shift? My tuner uses HP tuners, and used some of the current ZR1 shift speeds and pressure data on the TCM but that tune would go into limp mode when I hit the track so I flashed my old trans tune back in.

I forgot to mention my current ECU OS# is 12614088. The tuner I just started talking to said that OS is from a 07-09 truck with a 4l60. He thought that the ECU must of been program forced on a bench harness. Does that sound right?

Also I just came across OS compatibility for the TCM's. Mine originally was a 24237685, and a full flashed it to 24239353 so I could utilize tap shift.
the 2009 corvette TCM OS is 24251030, which is not compatible. With the 2 OS # listed above. Is there a way to flash my TCM to except the later OS, or is my tuner totally off base on this.