I realize I have to replace the starter unit on my 87 PU. I see on Rockauto that some of their replacement starters specify AUTO trans and others MANUEL. I didn't know there was a difference. What are the differences & do they matter?

 

I think it has to do with the amps as the Auto-trans one has to get more mass moving.
I put the one listed for the auto trans in my 5-speed no problem and boy does it jump to life quick.