Alternator Question!!! /6 work on 318???

I am going through the process of switching out the water pump pulley and crank pulleys I had that came off a AC car because I didn't realize they wouldnt work on my non A/C 74 Duster with 318. Now, I am wondering if my alternator will work or if i should switch that out too?? The only alternator I have is from the slant 6 my car originally had. Do I need to purchase a new alternator that works with a 318??? Thanks