This thread will cover a 5.3 install from 2009 Hummer, a harness and controller from a 2008 Tahoe and a 8 lug hvy dty rearend from an 2004 HD Truck. I will post pics as I start this weekend. This may take a few weeks to complete.
Starting with this engine!

 

Heres the engine after a few mods. Starting to tear the truck down. A pic of rear end and tranny.

 

Getting the engine ready to set in. Heres how to use your clam shell mounts on the LS for reinstalling. After a few measurements I determined that the original mounts will work. I took a 1/4'' plate and drilled holes to match original mounts on the LS block. Be sure to cut off the hump on the back of the clam shell so it can be welded flat onto the plate. Use the bottom hole of the clam shell mount and place over bottom hole and forward of the engine to bolt thru. Then notch where the upper bolt will go. Cheap LS engine mounts!

 

Cool Man kinda looks like mine.

 

A little progress! I had to flip the stock tensioner bracket so that the spring would pull up on the belt. I removed the stock idler pulley and exchanged for a smaller diameter pulley from a 1991 full size chevy truck V8. The headers were for a 2005 Silverado. All went well until the passenger side. I will modify the header rather than notch the frame. Mounts seem to fit just fine. Working on a mount that will use the trucks original AC compressor.

 

After a few hours this weekend the header for the passenger side has cylinder 2 exhaust rerouted into the number 4 cylinders pipe. This resolves problem of the pipe hitting the mount for the upper control arm rear bushing.

 

nice work!!! keep the build going!! good luck