Alright, started cleaning up the LS...
First step was to remove the wiring harness. It's basically three pieces, the main harness, the relay harness (fans & fuel pump) and the computer. I tagged everything as I went so I know what connections go to what sensors on the engine, it was a good way to get familiar with things. Since the engine was originally fitted with the throttle body at the back of the block, I'll need a few extension harnesses for some of the sensors on the intake manifold and throttle body. I'll probably need extension harnesses for the O2 sensors as well as I'm planning to go long tube and the bungs are close to the collector for the Texas Performance Concepts headers. There were a couple of wires I couldn't figure out, some back and forth with TurnKeyEngineSupply got it sorted out, they were the check engine light trigger wire and the 12 volt ignition switched wire heading to the coils, O2 sensors and alternator.
Next I removed the exhaust manifolds and pulled the plugs to check them all, nothing looked troubling, and gave the heads a quick clean.
Next I pulled off the valve covers to check the valve trains, everything looked fine, no signs of snapped push rods or broken springs. I have 706 heads, so I checked to be sure the embossed Castech logo wasn't present under the valve cover as well. There was a run of Castech heads that were bad (porous I think), so I didn't want to see the little battery shaped casting pictured below. It was not there, it was a different casting logo, so all is well so far.