Try the suggestion John recommended by disconnecting the linkage. If the shifts are still late, drop the valve body and check the throttle pressure sleeve. There are two valves, a spring and a sleeve that go in the throttle valve bore. The last part to go in, the sleeve, has one end where the inner diameter is smaller than the other but it will fit over the other valve either way. If you install the sleeve with the smaller inner diameter first, you will have problems very similar to what you are experiencing. The sleeve must be installed with the large inner diameter towards the valve body. Also check that the throttle valve isn't hung up against something.