I wanted to post this because I have been building a 5.3 with an LS1 intake for my 55.1 chevy 3100 and finally took a stab at the first start up. It took about three or four attempts to get it to start and here is the video. It was a bit louder than I expected. I have since hooked up an oil pressure gauge and on the next start up I will check the oil pressure, and also check to see if there are any exhaust leaks. Other than that... any thoughts on what else may be going on?
More info: the engine had about 100 thousand miles on it (had roller tick) I swapped the cam and rollers. I fabbed the x pipe and the mufflers are stock c6 mufflers. its a 4l60e transmission from CL... starter is from CL... Throttle body, alternator and water pump are from CL...
http://youtu.be/o0T7nx_A7R4