Thanks guys. It's just the beginning to a long, drawn out build!
gearheadmb - The bellhousing pattern for the LS engines is essentially the same as the gen I smallblocks. LS engines use all metric fasteners. There are some caveats for using older trannies on the LS engines, for example in my case I will need a spacer at the back of the crank to support the nose of my torque converter. I bought a TCI flexplate and spacer that have the correct patterns and spacing to mate my LY6 to the TH400. Most LS engines require the spacer, some do not.