I've seen a lot on replacing the radiator, especially in the BB. Is this a given. Reason I ask... I just got a '73 with BB, completely stock, but i have not driven in warm weather yet. Runs fine so far, but i don't want summer here and find i should have taken the winter to replace it. I also have and would like to use A/C. Any suggestions welcome.

remember rust happens, water in contact with steel over 32 years, your gonna get some rust. antifreeze has rust inhibitors, but after 2 years, the inhibitors lose their effectiveness. i would at least change and flush the cooling system. one more thing, does your bb still have the fan shroud? this is a must on a bb.

If your radiator is not leaking, and you are not sure of its cooling ability, I would take the radiator to a good radiator shop where they can throughly flush it out and make sure it is good and healthy for summer. It will be cheaper than replacment. But first flush your whole cooling system before you remove the radiator. that way you can get some of the junk in your engine block out. Also check if all the seals around the radiator are in place and check your air dam and thermostat.

there are no leaks, shrouds are in place and look OK.. I will do the flush remove thermo and have radiator checked/rodded if necessary.I'm thinking if I need to have any work done on it i will just opt for the Alum Rad replacement. We have a pretty good & reliable radiator shop nearby... I'm planning on the spring fling and don't want to test it on that trip

thanks

I don't know why my first reply didn't come through, but here is my 2 cents.
I have a 74 4 on the floor BB. running temp was 200. I had the rad drained & flushed and replaced the stat. After all that, my car would go into the red within 15 miles. I redid all of the above again with no improvements. I purchased a DeWitts alum.rad w/dual fans, and a Edlebrock Vector water pump. I got stuck in traffic in Carlse PA (it was hot) with A/C on and never went over 200 degrees. Best money spent so far.
P.S.
Nice ride and good luck !

Did the you "burb" your cooling system after all that? sounds like air got trapped in it.

I re-cored mine (also a big block) I went with a closer fin spacing, 18 instead of the stock 12 if memory serves. That way I kept the stock look and improved cooling substantially. I can let the car sit and idle for quite a while and the temp doesn't get over 160.
I did have heating problems at first Air Lock in the system. I followed advice from Ben and drilled a couple of holes in the t stat, problem solved.

I've heard some guys put an aspirin to hold the thermostat open before you put it in. That way all the air finds it's way out and then dissolves in a minute or two. Wadda ya think? Cool idea?

blu72 said: I've heard some guys put an aspirin to hold the thermostat open before you put it in. That way all the air finds it's way out and then dissolves in a minute or two. Wadda ya think? Cool idea?

three 1/8" holes drilled in the thermostats is the primary difference in a thermostat and "hi flow" thermostat..

and it solves the burping problem