Setting timing on a 4.9 l v6 1996 F150
 

I want to change the distributors i found the TDC on the crank shaft pulley and i lined it up with the pointer and took number 1 spark plug and the piston is all the way to the top of cylinder but on my old distributor the rotor is not pointing to the number 1 spark plug.any ideas on what i need to do? i bought this truck and previous owner has no idea what happened to it or what is wrong so i'm starting from scratch trying to figure it out on my own. thanks in advance.