i replaced my upper and lower intake car idles high to 300rpm then shuts off

Did you mean 3000 rpms? 1.Make sure that there is no open vacuum line. 2. Make sure that there is no sensor unplugged. 3. It maybe possible that the push rods are in wrong. Hope these suggestions lead you in the right direction.

If you have a security system it may be activated by disconnecting battery. close all doors, lock and unlock drivers door only, then try to start car