starting problems

[hubkap]

Have a 1979 F250 w/300 6cyl. 4spd. Have replaced starter and solenoid and still get scratchy screeching sound. But never turns engine over. Have exactly same problem w/1974 F250 highboy w/390 4spd. Have new battery in both also. Ring gears look fine on both trucks.
Any advice greatly appreciated. :)

[Mr_Mac]

Not much to go on, so forgive the question...can you turn the engine over by hand?

[hubkap]

yup both turn over by hand and both will start when pulled in gear

[Mr_Mac]

Next question: Can you have someone look and ensure that the starter gear is in fact engaging the flywheel and not just partially coming out/hitting the flywheel?

[hubkap]

Ground cables were dirty both trucks-cleaned ends and engine block and all is good now :)