[Walt Fricke]

Timmy's suggestion is the simplest - get one of the limiters which goes into the distributor. You can pretty much set those where you want them by bending the tab which holds one end of their spring this way or that - out is higher limit, in is lower. Of course, if you can get one in the flavor you want, that's the simplest.

It isn't much of a safety feature, though. It only helps if you get a stuck throttle in neutral or with the clutch in. Above 7,000 RPM the engine starts getting asthmatic, and it won't spin up a lot farther. Certainly not before you can do something about it, like turn the key off.

It won't save you from the money shift, alas. And when in gear with the accelerator working normally, I don't think you can directly damage the motor because it is going to run out of breath and you will realize from the extra noise and the fall off in acceleration that you should upshift.