I just got the engine (350) in my 75 Camaro running but its blowing white smoke The guy I bought it from had never started it( project car that he never started). The car has been sitting for a while, the gas in the tank was nothing but varnish etc) I replaced the water pump, the thermostat and hoses last week becuase when I fired it up the first time there was water leaking out the weep hole in the water pump. When I started it up after putting on the carb after I rebuilt it, it started to smoke white smoke out the tailpipe, I dont have the gauges hooked up (tonight I will) so I dont know what the temp was reading, it runs and starts fine, I ran it for about 5 mins or so and it idled fine, sounded strong, I reved it by hand a couple of times no misses or anything. I shut it off and let it set a minute and it restarted fine. The thermostat did open, I could tell since I was watching the radiator with the cap off so I'd know when to add water/antifreeze. Do I have a blown head gasket or just a leaking intake or what, is there a way to troubleshoot this? Any help would be greatly appreciated.Thanks.

Did you change the oil? If the car has been sitting for a long period of time, its possible that condensation has accumulated in the oil. What you may be seeing is it's finally burning off. If you don't let engines get to temp, this is a common problem.
You may have a blown head gasket too, but I would change the oil and take a look at the old stuff and check to see if it looks milky.

Thanks for the response, I did change the oil already, I used 10w30, a friend suggested that I may need to use 10w40 or 20 50 weight. I will check the oil tonight when I get home to see if it looks milky or not.

When I first got my car it was blowing some white smoke. Put a leak tester on the radiator and coolant was leaking all around the intake. Installed some good Fel-Pro gaskets-problem solved. Good luck.

When you looked in the radiator, did you see any bubbles?
Blown head gaskets leaking coolant will blow bubbles in the radiator.
Water also cleanes spark plugs real good, do you have any that look nice and white?

I havent seen any bubbles in the radiator, I just put a new set of plugs in 2 days ago so I will pull them to see what they look like. I checked the oil and it dosent look milky at all, and its not overfull either. I did notice that the 2 inside intake bolts were loose, I torqued them back down but it didnt change anything. It seemed to get worse the longer the engine ran, it gives a quick puff when it first starts but the longer it runs the more smoke seems to come out. Thanks for the help.

How about the vacuum modulator in the transmission?
I bought a cutlass cheap once cause the PO thought it was aboutto explode, darned thing looked like a misquito fogger going down the road!
Pull the vacuum line from the trans, and check for anytrans fluid in it.

Another one that was a real smoker was just "gunked up" The inside of the heads were sludged solid to the top of the valve springs! That one got the kerosene treatment. 2 quarts of kero in the crank, idle for half an hour, drain, change filter, repeat. After a few gallons ofcheap oil, cheap filters, and kero, she cleaned up real nice and didn't smoke anymore.