75 Impala build

[mrbee]

I'm doing a engine swap I had this Chev 350 engine in a Buick Regal. Always had plans on getting a nice chevy to put it in. Okay casting numbers on this engine is 3970010. It has stock heads, Comp roller rockers, had a comp cam but just switched to lunati cam 500 lift, airgap intake, edelbrock 600 carb, flat top pistons, full length headers which are giving me a problem, 3.73 gears, going to get an electric fan. When we swapped the engine into this impala it was running pretty fine besides a little lifter tap, but changed cam to a lunati cam and lifters and during the break-in no tapping but running to lean. Guy came over and said it needs to get more gas and it will be fine. So we had to stop the break in of the engine. It was running to hot because the headers were glowing red hot it turned the headers from black to grayish white color. Talked to the guy who came over and said its running to lean and he said changing the jets to give it more gas will do the trick. also we were trying to break it in with no fan shroud. We rand it a couple minutes about 4 times and it was overheating and the last time it shot out all the radiator fluid. I have a 180 degree thermastat and was told to get a 160dg, and i am going to get an electric fan some header wrap to save my plugs because it burned a few and am going to get an edelbrock calibration kit part number 1487 that is supposed to give it more gas since it is running so lean because i can't afford to get another carb right now. Hoping that doing all this will have it running good and the guy who is installing my engine can go ahead with the break in tomorrow. Also its a 350 tranny with 1800 or 2000 stall i really can't remember. What do u guys think about my set up. The guy said it should put out around 310 horses with this set up. Also what do u guys think about it running so lean now was it the changing of the cam? Before I changed the cam the timing was set to -3 i think to run on 87-89 gas if i wanted to The guy who is doing the engine now said he was going to keep it that way although he said it should be at -0. Let me know what u experts think about all this! I guess this may be a lot to read but I'm trying to let u all get a good understanding of what is going on. I'm no engine builder but i do want to learn. Thanks guys!