1976 Chevy 350 turns over but will not start?

there are many things that will cause an engine to turn over ,but not start. 1-no fuel getting to the engine 2- no spark 3- timing off 4- no compression these are a few of the common causes, there are many more ANOTHER ANSWER The above is EXACTLY right, and you should check the potential problems in that order. Try a little starting fluid to see if the engine will start briefly that way, but before you do that you should probably check to see if it's getting flooded. If it's getting TOO much fuel starting fluid won't help. Next, check the spark. Pull a plug wire and connect it to an old plug that you lay on the metal of the engine somewhere. Have someone crank the engine and watch for a spark. If you don't get one, that's a good place to start. If you DO have a spark, check the timing. You can get close enough using a timing light and have the friend try to start it again. Last, if all of the above look good, run a compression test.