Well guys this wiper motor does not fit. I will return it. Here is a picture of the firewall wiper motor receptacle.
Do you know what the correct motor is that fits this? It's sort of a well the motor fits into, like a cup shape. My truck is a 1965 GMC 1000 with the 305 V6.
Thanks Roger

Okay I can't get the image up. Please look at it in my gallery, the pic is named: firewall wiper motor recepticle