6.0l LQ4 to old school tranny

[softballnrd27]

I want to make sure I have this right:
2004 LQ4(not sure what trans was behind it, I forgot to ask) I am posting a pic so that maybe it will help with what I need to know:

I need to adapt my th350 to the 6.0 If it did in fact come with a 4l80e then I should be good as far as spacer and bolts correct? If not then I need to get the spacer and bolts correct? Then I need the flat flexplate and drill holes for the th350 TC? When I go to mark the holes in order to drill new ones, does it matter where on the flexpalte they are drilled? Should there be a certain distance from the factory holes?