I just did an oil change and and replaced the neutral safety switch and now my engine will not start. Turns over just fine but will not start. Any suggestions??

 

If it turns over, that means the NSS was adjusted correctly after you R&R'd it.

so now, do you have spark coming from the coil to the plugs, do you have gas in the carb?

Pull the coil wire out of the dist cap and hold it (use insulated pliers so you don't get knocked on your ***) about 1/4 from and unpainted part on the engine. crank it, spark? if yes, put it back and pull a plug wire off of a spark plug and do the same. if spark , its not electrical. (unless the plugs are fouled) If no spark it could be the point gap, the voltage to the coil is missing, the rotor or the cap.

Next, spray some starting fluid in the carb, if it tries to start, then it's got spark but no fuel. You'll haver to figure out why. I'll leave you there for know.

 

Once my 68' didn't want to start, had a good sparkor soit seemed, but come to find out the coil was very weak. It seems like it should have started and once the coil was replaced, it did. just my 2 cents

 

if it ran perfectly fine, then my guess is that you accidentally pulled a cable while doing that work ?!
as jlg2002 says, the switch can either be on or off. and if you had that wrong, the car wouldn't turn over at all.
Did you pull a ground lead from battery to engine?
check if you get spark first. If you don't know how to test this let us know

 

Found the problemlast night, some how my carb lost prime and the fuel pump would not re fill it. So I primed the carb with fuel and its back to normal again. That was just weird.
Thanks for the help.