[Plums]

While it's true that they are getting great results with the E38, it doesn't tell the whole story. The E38 is missing some of the great functions that were available with the older PCM's. E.G. Lean Cruise doesn't exsist in the E38 due to the stricter emissions requirements it must meet...
I'm pretty sure no engineer would pick the change.

I'm pretty sure you don't need to change the cam in an L76 to run the LS1 PCM. If you do change the cam you need to change the lifters I believe.

Rebel is right, the L76/L92 heads would be right at home with over 400 cubes, and when combined with a tasty cam and valvetrain should see around 350 rwkW's with awesome grunt down low.....