would a coroded dist. rotor cause a slow turn over when motor is warm...

no. Always had this prob or recent?. I'd suggest cleaning all of the connections on the large cables starting w the batt positive post all the way around to the neg post. Still bad, borrow another battery to sub in to test it. Starter could be going bad but the easy things 1st.

To much initial timing can cause starter drag when the engine is hot.