Ditchpig

Alright!! I just installed a 20R into my truck from 1978. Everything went well except for 1 thing!! ALL the connectors for my electrical system are different. I have the matching starter hanging around but I don't know if it's any good. Is there a way to see if it spins? I tried hooking up the proper wires to it on the harness and turned the ignition but nothing happened. The starter was the only thing hooked up. Should it have worked? Any info would be great and I'm guessing that I'm going to have to get butt splicing my connectors!!