by "Password protect" i need the governor to be "Locked" in the sense that it cannot be altered once it is put in, without a password or code to unlock it. it wouldn't matter if the only way to undo the governor would be to take it to the dealer, but i don't know if there is a way to accomplish that.
As was said, the only real option, other than getting a tuner that has a speed limiting function, you can setup one of your keys as a slave key to the Admin key. You can do all that through the info center in the dash. You can set the slave key so that when it is used to start the truck, it has a set speed limiter and the radio will not play unless the occupants are wearing seat belts and one or two other options. Then the other key will be an admin key, which will function normal. The only way to revert the slave key is by having both keys available.
As far as a tuner, you can load a tune and input your own top speed limiter. Then the only way to remove the limiter, no matter who is operating the truck, is to have the tuning device in hand and re-flash the truck. I would opt for using the mykey system.
If you have a programmer you can set the top speed to whatever you like even if it is 55mph I think on my programmer it tops out at 199 or 200? But the fastest i have gone so far is 155 per gps and programmer. Although after a fer runs like that i had to get new tires as they were trashed. If any one knows of a high speed rated tire let me know, the highest i have found is the Goodyear silent armor Kevlar I believe they are rated to go up to 118 , which is much better than the "Q" that must truck tires are (or less) since the govonor is 95 on fords and 9? on the the HD's. hope that answered your question just hope you have a programmer.
Just asking a genuine question, but why in the wide world of sports would you run a 4 ton pickup truck at 155mph, multiple times????