Engine and Transmission Tech

i am in the middle of converting my mgb to a v8 its a Buick 215 and i am a little nuvouse about over heating as it seem that all my cars want to dran there water my ranger pump broke and let all the water dran out and the mg cut up 2 radiators then i drove my dads MG and it cut up a radiator to ):
so how hard is it to mess up the engine when it over heats, and could i install a temp sensitive switch that would kill the engine if it starts to get too hot just in case i miss it over heating till its too late

Your cars evidently overheated because something broke. That's a bit different from having marginal capacity and then being pushed too far (for example because of being stuck in a traffic jam on a 120 degree day.)

Your temp-sensing engine shutdown switch isn't necessarily a bad idea, but...

IMHO, the right way to avoid overheating is to design/build a robust system in the first place and then do proper preventive maintenance so it stays reliable. In simple words: DON'T CUT CORNERS! You shouldn't have to be nervous and frankly I don't think you should have to drive around with one eye on your gauges either.

Buick 215s aren't particularly fragile and they're not particularly hard to cool. Generally, cooling system size needs to be proportional to engine output. An original 1971 MGB radiator core cooled my Buick 215 for years, until I bumped up compression ratio and thus horsepower. (The MGB radiator was fitted with oversized ports and its mounting features were changed.)

well I am going to put a larger radiator in there car with an electric fan to help with cooling I just don't want to miss it over heating and destroy my engine for example in the summer time I like to go on this road that goes up and over the pass its very curvy and fun to drive on but I for get to keep an eye on the gage and it over heats the switch would shut it down before anything really bad happened

I wouldn't put an overheat shut down in the car.
What if it shut your car down at a critical moment and you had a crash?
A better idea might be a warning lamp. If you really want to notice it, use a big one. You could tie it into the low oil pressure switch and the brake warning as well. That way if it came on you know you have to shut the car down immediately.
For a switch, lots of the older chevy's etc. from the sixties had one that turned a light on when the engine overheated.
If you have a good guy at the parts store they should be pretty easy to find.
I have one in my TGB that turns the seat heaters on until the engine gets warm enough to run the climate system. Then if it overheats all the fans get locked on high and the ac gets shut down. (never had it activate but, just in case.)
The switch I used was for a 62 Pontiac if I remember correctly. It has two terminals. One that grounds when the engine is cold and one that grounds when overheat temp is reached.
Hope that helps
Cheers
Fred

DiDueColpi,
that's a much better idea and probably easier