The Haynes manual I have lists two bolt sizes - 8 mm and 10 mm. The existing bolt seems to be 10 mm.

However, the hole in the new bushing is 11mm. This seems like far more slop than should exist in a part on which I'm torquing the installation bolt. Is this normal, or did NAPA sell me a faulty part?

For critical safety parts, any nut/bolt that requires additional rotation after getting torqued should not be reused. The reason for the additional tightening is that most torque wrenches do not measure that high. The nut threads and bolt may also be slightly stretched in the process, making it too weak to be stretched twice.

As to the top engine support, I do not understand why it is torqued so high. Then, I put in a plastic bushing which will not spread under load.

Klaus
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Always willing to listen, just not able to take direction.

I am in the process of doing this on my 1994.
I found that the new bushing I got from FCP is bigger than the one that came out, and it can't go in. There seems to be two diameters.
Check the diameter of the one in your car with calipers.
It may be either 2.38" (60.4 mm) dia. or 2.32" (58.9 mm).
I can get some pics if it will help.

If your new one is smaller, then it will be loose in the mount. If bigger, then it won't go in. I hope they are the same.

Personally, I will just use the same nut and bolt, and just torque it.
But for items that I want to make sure I do it right (like wheel hub nut) I judge the angle by eye. Before angle tightening, I note where the power bar will be when it is moved another 60 degrees.