I've searched for hours with no luck so i figgered i ask, I have a 78 f150 with a 400 and a 4 speed transmission.I know manuals have 180 teeth on the flywheel and I believe autos have 164 teeth. Is there a differnce in starters between manual and automatic transmissions? Any help would be greatly appreciated, thanks.

 

Yes there is a difference and neither will work in the others place. Something to do with the nose length, not sure about the teeth count.

I know that when you go to the parts store it matters what trans you have.

 

As stated, they are different. The starter drive gear on an automatic protrudes into the bell housing about 3/8" further than a manual. You can verify this if you ever have a flexplate and flywheel lying around. Laying them flat, you will see the ring gear on the flex plate sits about 3/8" further aft than where the ring gear on a flywheel would be. Now these are stock configurations in talking about. If you do any business with L&L, they will say you can use the auto starter for a 400 on a swapped in 460 flywheel. That's a whole other subject.

 

Here's the starter application page from the truck parts catalog. There is NO DIFFERENCE for 351M/400 starters for A/T & M/T, they are exactly the same!

 

I agree with NumberDummy on the starters being the same (the parts catalog page says it all).

With less authority, I have a handful of original owner Fords in my line up and the 351M/400 automatic/manual transmission starters are the same from my amateur wrenching experience.

Starter applications seem to be one of many mixed up things on these old trucks. Between mis-information at the parts stores and years of "this one looks like it will fit" parts swapping by several owners, the applications get pretty blurry. I have learned to either repair my own original starters or take them to a reputable rebuilding shop. I have seen too many starters that got exchanged for the wrong one at the parts store and by the time the well meaning individual figured out what was going on the original starter that he traded was long gone. Yes, the parts store starters are a cheap & easy fix but they don't always work out as well as the original. The exception is to buy a remanufactured unit from a Ford dealer; I haven't done that in years but they were always the correct starters.

Sorry if I am a little off topic. Just trying to share some of my limited experience.