[Formulajones]

Originally Posted by 462ta

where are u guys getting the springs no parts places over here can get them

Here's where I buy the stainless version, just last year when doing my SCJ, however they will work in any application, even if you have to trim them.

http://www.cjponyparts.com/lower-rad...-1973/p/HW769/

[Schurkey]

First Guess: With the engine at less than 2500 RPM, fully warmed-up, and a proper radiator cap, there is no way in hell the lower hose can collapse. It'll be hard with pressure. The pump can't generate enough "suction" at that speed to collapse a hose that's been appropriately pressurized by a functioning rad cap. (Unless the radiator is plugged with scale, so that the radiator tubes become an unreasonable restriction to flow.)

The FIRST thing I'd check is to see if the system holds pressure--do the hoses get hard when the engine is hot?



I have to assume that you've got a 180 thermostat. Your temperature was borderline at 50 mph, and overheating at 60. I'd be looking at the water pump, advance curve, and fuel curve.

Do you still have the rubber seal that contacts the hood near the windshield?

[Formulajones]

Speaking of seals, since this is a 70-73 bird, and having one myself, they were sometimes built (depending on plant and options) with the core support cover. Some have them and some don't. It stretches from the core support and tucks up under the nose and seals off that area in front of the radiator. A common place for air to escape before it passes through the radiator. You may or may not have one. Having one forces air through the radiator with no where else to go, usually seen on AC cars.

I know this problem just cropped up recently and wouldn't contribute, but worth mentioning.

[462ta]

cap is good hoses get rock hard
advance is working, with timing light discon advance and rev engine them reconnect and rev and you can see difference in timing
when get a chance will look at fuel but all indications look to be on the rich side
water pump seems ok ,with rad down a bit and rev engine water was shooting out tubes,plate was clearanced to impellar before install

["QUICK-SILVER"]

Originally Posted by 462ta

advance is working, with timing light discon advance and rev engine them reconnect and rev and you can see difference in timing

Might need to check this again. Need to be looking for proper timing advance without the vacuum advance hooked up. Non functional vacuum advance usually doesn't cause overheating. So it doesn't really matter if it's working or not.
Non functional centrifical advance is guranteed to cause overheating with increased RPM.
And centrifical advances can freeze up at any time without warning. Centrifical advance does not have to be froze solid either. If it's just tight enough to restrict/limit advance overheating will still occur just at higher RPM.

+ Depending upon engine and how original things are under the hood; if the heat crossover is still there and functional, the flap can get stuck shut and the engine will overheat with speed. Especially with warmer temperatures outside.

Clay