I ordered batteries a week ago. 16 Deka GC15G with universal posts. The universal posts seemed to be the beefiest post available with a bolt-through attachment. The place I bought them at doesnt keep the GC15 in stock with this post so they ordered them from the factory, to be delivered right to my house. It will be another few weeks.
In the mean time I pulled everything back out and changed the throwout bearing in the clutch. There was a terrible noise when the clutch was engaged (pedal up). It went away when the pedal was pressed. A mechanic said that indicates a bad throwout bearing. Almost $40 later it still makes the noise though a bit quieter. I think it must be the bearing in the motor adapter/extender. That means I have to pull it all apart again. But it only takes a couple hours for me to do by myself! Once I get the batteries in I'll take it to my mechanic (father-in-law) and have him help me pull the adapter apart to check that bearing, which I suspect is not a thrust type bearing.
I got the tachometer working! I added a reed switch (not in photo) to pickup the two magnets I had mounted on the back of the A/C pulley. I had to borrow an oscilloscope from work to figure out what was going on. I was afraid I'd have to use a circuit to adjust the signal to something the tach could read, but all I had to do was add a level shifter circuit consisting of two resistors and a capacitor.