I have a 1984 F250 with a 351w and a c6 transmission.The problem I am having is the starter teeth aren't engaged far enough in the flexplate,and it make a grinding noise and will not crank.I have replaced the flexplate and the new one is a Pioneer FRA202 which is a 164 tooth flexplate,and the starter has been replaced with a 9 tooth starter.I have tried 4 diffrent starters from diffrent parts stores all with the same results. Seems like the starter is to far from the Flexplate.

 

You've probably already addressed this, but are the starters you've been getting for an automatic trans vs. a manual? The nosecone on the autos is longer than the manual (which is just a stub nose), so if its too short, the starter won't engage the flexplate.

 

Yes I am getting the automatic starters. I painted the pinion gear on the starter, and it contacted about a quater of the way in the teeth of the starter then I repainted the gear and when it messed up the gear seemed to skip over the teeth of the flexplate.

 

I would normally want to suspect the Bendix® drive of the starter motor, this is the assembly that springs the starter's gear to the flywheel/flexplate and turns the engine but doesn't allow the engine to turn the starter motor.

Bendix drive - Wikipedia, the free encyclopedia
Starter motor - Wikipedia, the free encyclopedia

But you say you've tried 4 different starter motors with the same result, that would imply the problem is someplace else but I can't imagine what that might be....

 

Was this problem always there? Or did it only start after you replaced the flexplate with the Pioneer model......Reason I ask...there are different offsets that Pioneer made....the FRA202 and the FRA205 are two that occasionally get misplaced with one-another, either causing a problem with the starter (like you have) and/or a problem with the torque converter not matching the mounting holes just right. It might be worth a phone call

Flexplate help anyone [Archive] - ClassicBroncos.com Forums
Cat in a blender [Archive] - ClassicBroncos.com Forums

 

When I got the truck it made a loud ringing type noise and one day it started this and I have had no luck with it. Thae plate between the motor and the transmission has a bend in it, at the starter opening it is bent in towards the transmission. But I figure the mounting ears on the starter would line it up ok.

 

I had the same problem today...I read your link trying to find an answer..
My little dust cover/plate thing is bent in too and that is what is supposed to hold the starter from doing any side to side play, since there are only two mounting bolts...What ended up working for me is I put two washers under the lower bolt between the starter and transmission, I didn't put any under the top bolt. This gave me the angle. Fires up repeatedly with no grinding
Good luck

 

Do you remember what the thickness of the washers were?

 

They were just standard washer thickness...not anything special, you might want to try different combinations too. I put them on both bolts then tried just the lower bolt and it worked if it doesn't work the first time, don't give up!