Got my adapter kit from Jim Carter Truck Parts. Where did you get yours? Put new Fenco 10-1331 MC(designed for a 3/4 ton pickup) in this afternoon, but will have to wait on neighbor for help bleeding. Push rod was only about 4 inches long with over an inch of threads. When run all the way in the coupler, the whole thing is about 4 inches long.

When I bench bled this master cylinder, it was moving fluid pretty well, so think this one will work once brakes are bled. Will keep you posted.

Still curious where you got your adapter kit.