Young mechanic learns something new. Problem fixed, now a new question.

[lvin4jc]

My '63 has been running warm, very warm since the weather turned nice outside. It's been anywhere from 3/4 to all the way up the stock gauge. But when it got all the way up if I took it easy on the old girl the temp comes back down to the 3/4 mark. I thought that if a thermostat was bad the temp would get hotter and hotter until the engine eventually blew up. So i've been spending my afternoons flushing out the radiator, cleaning it, flushing it out again several times etc. I finally decided to pull the thermostat and boil it, sure enough the 160 degree thermostat never opened even after the water was boiling. I put it together without a stat and the truck runs cool as a cucumber, between the quarter and half marks on the stock gauge. Problem fixed.

Now I have a new question. I have been running at 40-45mph because the truck would warm up too fast at higher speeds. I had only had the truck up to about 55 mph so far and that was just for a few seconds. Now that it runs cool it could potentially run a little faster. I ran it up to 70 mph today just there and right back down just to see how it did. It did it fine but i'm quite sure the truck doesn't want to do that for any length of time. And I don't need it to either. I drive backroads and if I could consistently drive 50 mph or even 55 mph for 15 minutes at a time that would be great. At 50 MPH the truck is turning 2,500 RPM. This is a 305 V6 truck. So I guess my question is what was the speed limit in 1963 and what speed is the truck designed to drive at for long periods of time?

- Joe -