1973 Chevy El Camino wont start

Engine Mechanical problem
1973 Chevy El Camino V8 Two Wheel Drive Automatic

i had my motor rebuilt drove it from colorado to ohio when I got to ohio I could smell gas in the oil I changed oil and filter took it for a drive it was slugish when I stepped into it, it died since then ive torn it down realigned the timing replaced the fuel pump, starter, battery, coil, it started before I put it back together but now wont start any ideas or suggestions