I have a friend who is tuning a 2006 gmc 6.0 truck. The truck was originally equipped with a 4L65E and I installed a FLT level 5 4L80E. I repinned the case connector and built an ISS harness.

The tuner is having trouble finding a matching OS(12606807) that includes a 4L80E segment, to use for a segment swap. As far as I know he can choose any 6.0L/ 4L80e OS and load it into the PCM. However, he is thinking that that PCM will only accept OS 12606807.

Is there something about the late PCMs that will not allow a complete OS swap, or does it just have to be one of only a few compatable Os?

Thanks in advance!