When starting the starter gets kicked back

When starting the starter gets kicked back. I have replaced the timing chain, timing is set (yes with the connector under the dash disconnected), it was running pretty rough for a while but I replaced the cap, rotor, wires, plugs, and coil as somewhere in there a problem was causing a lot of corrosion build up (i think when the previous owner changed the spark timing in order to compensate for the timing chain being so stretched. The truck still has a slight misfire, but the problem is the starter kick back its already taken out 2 starters on me, luckily I have the lifetime warranty but replacing it every other week is getting annoying.