HELP ASAP-new motor

[SMoKeM240]

im trying to start my rebuilt motor and i can get it to crank, but nothing... then i switched the 1st and 4th plug wires and now it cranks and back fires a little after a few secs of cranking.. what does that mean, and why wont it start

[SMoKeM240]

well i took the cap off and put the motor at TDC and the rotor does not point at the 5oclock spot where 1# is at, so i guess my oil pump was put in wrong, so let my try that and see

[Red coupe]

just set the engine to tdc on compression stroke(set to tdc then check to see if the cam lobes are pointing outward by looking in though the oil filler cap, if not rotate around one more time and check again) then unbolt the distributer and pull it out, next turn then distributer so that the rotor is a little before 1st(when you push the distributer back in it will turn 20-30 degrees because of the spiraling gear.). Its easyest to do with the cap off get it all set and make sure its still fine after its inplace then bolt the cap back on, and then time. should help...