Identification on used Mopar Crate 360

Have you asked the guy? Maybe he has some paperwork or remembers exactly what it was.

I don't think you are going to get any more info, I just don't think there is a good answer. Doesn't appear that MP leave any marks on the motor to help you.

You can tell some by what heads it has, LA heads equals 360 hp, Magnum heads equals 380, Magnum RT (maybe) equals 390. Beyond that you need to get into the motor and measure the cam duration and lift to get a better idea.