I know it wouldn't be called idea, but how effective is a FMU at tuning an otherwise stock engine with a blower added?

Looking at buying a truck that has a powerdyne blower, and it looks like the kit was installed with the FMU instead of retuning the PCM. I'm wondering how big of a risk it is that the engine is on its last legs. Its at 176K so anything is possible, but anyone who knows FMU tuning or centris better may be able to speak to it.

For reference, I'm looking at buying this partially because I have a trans with 67K on it, and a 5.3 I just put together with a boost friendly cam (228/222 114.5). Like any modified vehicle you run the risk of it being beat to shit regardless, I realize that, but it appears to be in good shape otherwise. Also, I really want to know who (besides me) puts a blower on a 4x4 ext cab truck, because I thought I was the only person on earth that though that sounded like fun.

Thoughts and input from the peanut gallery appreciated!