Got a question for ya?

O.K. I just had to put a new motor in my 98 chevy s-10. It has a 2.2 liter motor with a standard transmission in it. The new motor I put in it has 32,000 miles on it. Before I tore the other motor up I was having trouble starting it. For a while I could turn the key on and it would start perfectly, then maybe the same day turn the key on and the lights and evrything come on like normal but when u turn the key to start it, nothing would happen. So I would just push it off and it would start fine. I always thought it was the starter, so when I put the new motor in I replaced the starter. I still have it up on ramps from putting the new motor in. I tried to start it after I got everything hooked back up and it still does the same thing. Wont start with the key, and not sure if it will push off and start or not. I really want to get this fixed so I wont have to do this. I have checked all the connections to the starter, checked all fuses, have a good battery, I dont know what else to check? One of my friends told me that it could be in the key switch? But how could I check it without having to buy a new one? Oh yeah, the motor that I put in is the same year and everything matched up the same and I have all the ground wires hooked up also. If anyone has an answer to my problem? I would greatly appreciate it if u could help me! I have tried everything I know to do besides the key switch. And the new starter and the old starter are both good, because I checked them both.