All,
Since I've been creating these for Circuit Specialist use, I figured I'd go ahead and share with the forum as well.
Attached are listings of (most of) the connectors for building a brand new engine harness. They are broken down into Gen III (LS1/LS6/LM7/LQ4/etc.) and Gen IV (LS2/LS3/LS7/L92/etc). Note that there are differences amongst the different engines of a generation (DBW throttle body and pedal combos for example). I also list a great source for wiring (DIYAutoTune's bundles are CHEAP and VERY nice TXL wire with labels and color coding).
I'll be adding a few more spreadsheets shortly with fuse boxes, glue shrink, etc. If you find any errors or have any questions, please let me know.
Regards,
Blake