[Ed Pitts]

"Take your flathead starter apart. Keep the long through-bolts and end plate with the armature and bendix. Turn the armature if required. Don't under-cut the copper bars on armature. Use the starter from 332, 352, 360, 390 or 406 c.i. Ford FE engines as the conversion starter. Disassemble the FE starter. Keep the end plate with brushes and case with field coils. Check the bushing in the end plate and replace if necessary. The wire size and number of windings on the FE and flathead armatures and they are the same.

Now is also a good time to install new brushes. Install the flathead armature into the FE case. Install the FE end plate with brushes. Put long through-bolts in starter.

You now have a flathead starter capable of cranking an engine of 300 to 400 c.i. ,up to11 to 1 compression ratio. The finished starter looks like the flathead starter and you did it yourself."

This works. I have done this for two 12 volt starter conversions. On the last one I got a rebuilt starter from O'Rileys to use the case. It was for a 1964 Ford Galaxie; 390 cu in. engine. The part # is 03-0214 and the line is ULT. Cost was $39.99 plus 20 bucks for the core. So, for 60 bucks, you can have a 12 volt starter that works great.
Ed