Not sure what block you have. In my LT1 the sensor went straight in without any leakage and with out the adapter. Now I just need to get it wired in to the gauge.
In my 76 I had the same issue with it not starting with the key. What it ended up being is the efi plug that goes from the main harness behind the dash to the ecu harness. I ended up using a jumper in it so power would get to my ignition. I can try to get a few pics of it when I re-take my dash off for repairs (again).
If it is already registured in Nevada then you wont have to get it inspected. Even still they don't really have a reason not to as long as you have a title and passed smog, down here in clark county we still have to smog
Jo-anns, micheals, ebay... ect...
Can't wait to see how it comes out.
If you have the cash try this out.
http://www.alsacorp.com/products/sheetingfx/carbon.fiber.htm
For some reason I thought I had a picture of mine installed,guess not. Here it is sitting on the table when I first got it.
here are a few pics I took last night