Over heated

Only time will tell. You put a brand new motor in a 15 year old truck and didn't change the hoses?

Whitelightning

Keep an eye down the road on your coolant level for radiator or head gasket leaks just in case you managed to warp the heads a wee bit (check engine oil for water/coolant contamination). Good luck.

Franko

and ran about 5

damage? runs good no

Anybody that would drive five miles with their temp gage in the red is a real gambler, but not a good one to gamble against those odds. Of course I don't have money to burn so I may think differently.

i have had to do that a few times, and never had a problem yet. part luck, and part going fast to nearest water 4 miles with NONE. old john but wait and see, if it is damaged, you will soon know. oj

Yes 5 miles in the red with no water is asking for trouble. Time will tell if you seriously damaged it.

My comment was not meant unkindly though. If you've been around long enough these situations arise where the emergency outweighs the cost and you take that chance. I was real lucky to drive a V8 about four miles fast with no radiator once. I traded the car about 60,000 miles later with no problems during that time.