I have been driving a 1994 toyota pickup for 6 years.When it gets cold I turn the heater full blast.Then, after it is good and toasty, I back off/turn off the heater.

Every I time I turn off my heater (from full blast) my water temp gauge goes to the right almost to the tip of the red.It has been doing this since I have owned it.

Is this a common characteristic of a toyota pickup?

Toyota heater systems are a little quircky. But If it has been doing that since you had it no problems I wouldn't worry about it. As long as it keeps you nice warm truck gets you there back again. That's all that matters.

if you have coolant and it doesnt overheat dont worry about it...