OK 78 F150 351M, cammed, headers, unknown if head work; I had a fuel leak last week near the tank and turned the engine over many times for quite a while. Drained the battery. Charged it back up. Starter just spun after this, didn't sound like it was engaging the ring gear at all. I checked all the wires and found the starter was right against the headers.

I ordered a BD Electric PMGR Mini high torque starter for a 1995 460, received it, changed the wiring as instructed(and confirmed it with many threads I searched for here). It still just spins but doesn't engage the ring gear.
I changed the relay even(good idea, pretty abused mud truck when I got it); still just spins.

I think it must be a auto starter and extends out too far to engage so I may need to shim it with one or two Ford .010 shims and the teeth will engage, or am I wrong?

I've searched for 2 days here and need more help.....

 

I know you said it should be OK, but can you please describe how it's wired?

Shouldn't need any shims so long as it's the correct starter.

 

Hot side of relay to top lead on starter, switch side to bottom lead(New wire that came with starter).

 

Here is what I found on the options for starters.

"One other item you can use on your 429/460 is a 92-93 7.5L F-Series gear-reduction starter. They are smaller, weigh less, and have more torque than the standard full-size Ford 351M/400/429/460 starters. If you plan to install headers on your Bronco with a 429/460 engine, then the gear-reduction starter will give you a little more room to work with in a cramped engine compartment."

Does that mean a 92-93 7.5L F-Series gear-reduction starter will work on a 351M, yes if I read it correctly.

I also read up on the additional wiring needed, trying to locate it. I would also think that there is a difference in the starter for a standard trans versus a manual one? Why else would they ask?

 

"Top" and "bottom" are hard for me unless I'm looking right at it. But the hot side of the solenoid goes to the heavy lug on the starter-mounted solenoid, meaning you have to move the original starter cable to the other side of the solenoid. The switched side of the solenoid then goes to the smaller terminal on the starter-mounted solenoid. If that's what you've got, then you're good to go.

Another possibility is that the ring gear is stuck at a spot where there aren't any teeth; bumping the engine over with a breaker bar would solve that. Otherwise, perhaps some difference with automatic vs. manual transmission.

If you don't get much more traction here, the guys in the 335-series forum would probably know.