[Davidf]

Awesome, all great info. So, more of my initial thoughts:
1. I will definitely remove the oil pan and check/clean. New water pump, new knock sensors and valley cover, new rear main seal and cover gasket. New trans input shaft seal.
2. Steam line into heater hose nipple on my new aluminum radiator. The nipple has internal threads to accept a barbed fitting.
3. I will do my own wiring harness following LT1Swap.com. I know about HP Tuners and debating on the $400 up front cost, or just getting LT1Swap to remove VATS and emissions for $75. If I ever install a BTR Torque cam later down the road then I will probably pull the trigger on HP Tuners.
4. My thought was to buy Trailblazer SS exhaust manifolds. Are the Hooker better or cheaper? Definitely, the EGR stuff is going away.

Question:
1. How do you hook up throttle cable? Are there custom cables made for this purpose that are the correct length with the correct ends? I have not studied this part at all.
2. Will my stock perches and engine mounts work with the adapter plates (whether DD or Speed Engineering)?
3. What should I expect as far as interference with the LS stock a/c compressor.

Great advice on the exhaust bolts. Why not studs with copper nuts?

Then, there is the fuel system...I have pretty much decided on an external pump setup. Will use the vent line in the sender for the return and extend it to the bottom of the tank. I am also thinking I will fab up a fuel bucket that clamps to the pickup tube and will fit through the sender hole. The return will return into the bucket. My hope is that this will solve fuel starvation with low fuel levels. The question will be how large a hole to drill into the bottom of the bucket so it fills fast enough but does not drain too fast. My guess is to start with a 3/16" hole.