I have a freshly rebuilt starter, wired for 12v, when I bench tested it, it spun like a raped ape, over 1,000 rpm.
What is the normal speed for a T-Starter?
It doesn't have to run that fast The specifications of interest is stall torque (11 lb-ft) and ampere draw. See this thread: http://www.mtfca.com/discus/messages/179374/230594.html
The work of turning the engine will slow it down considerably, but it doesn't have to be very fast. After all, if a car will start with a quarter of a turn by hand it doesn't need to be spinning rapidly. Maybe one of the guys who rebuilds starters will come up with a number of RPM for a bench test.
That's 12 volts for ya. You "might" want to keep an extra bendix and a few springs on hand. Wink and a nudge. The engine needs to spin this fast:
It should spin much faster than that. Sounds like you have bearing drag. Most likely misalignment of the shaft bushing (T5105). Could be brush or commutator assembly errors too. The armature should spin freely with only a slight drag with the brushes down.
You don't EVEN want to know what a modern remanufactured starter will spin if 1000rpm scares you.