If you still have your original starter, all you need is a new solenoid to put it back in action. About $30 maybe.
If the old starter got turned in as a core and you want something that will work, see if they can cross reference to these numbers:
AC Delco #323-367 or GM # 10496873
These are the numbers for the heavy duty truck starter and it should have the correct terminals on the solenoid.