Best water pump for a Cuda 340 driven on the street?

[CudaHead]

I have a 70 Cuda 340 with A/C.
It is tending to overheat on the road.
I have already replaced the thermostat.
I will be ordering a new radiator from Glen Ray in the morning, 2998974 (the one on the Cuda looks correct but I found out it was not the correct number)
I was thinking I should replace the Water Pump while I'm in there.
What would I use. I see 6 blades and 8 blades. Would the 8 blade ones be ok for street use?

[Burdar]

The 6 blade pumps are for A/C applications because they spin the fan faster to get more air through the radiator.  Less blades are used to try and prevent cavitation. The 8 blade pumps are for non A/C cars which spin the fan slower.

They do sell and anti-cavitation plate that can be installed onto the pump.  It's supposed to help flow more coolant.  Some have said it works...others haven't had much luck with them.

Make sure you have all the correct pulleys for your A/C application.  If the ratios aren't right, it could cause overheating issues.

What thermostat are you running?  How hot is it getting on the road?  Are you running a stock fan?  A car that gets hot on the road is usually do to a plugged radiator or too small of one.  A car that overheats in traffic is usually an airflow problem.

[CudaHead]

Interesting, I would of thought the 8 blade one would of worked better. Thanks

I was driving back from the Moparty yesterday. It's a two hour drive for me.
When I had to stop for Stop Lights, the gauge would go from the middle to over three quarters. I was doing my best to never stop.
If I did stop the car, it would heat soak and be pegged when I restarted it back up.
I stayed on back roads because when I got over 60, the gauge would go up.
90 degrees outside and I could not turn on the A/C....bummer.

I have a 26 inch radiator with shroud and a five blade fan. Should that be an 7 blade one?

[Burdar]

I think 340s used a 7 blade clutch fan. Do you have a clutch fan on it now? The fan should be half "in" and half "out" of the shroud.

[CudaHead]

I thought it should of been 7 blade also. I will call Tony's tomorrow.
The fan is sitting correctly and has a clutch.

[Chryco Psycho]

Is the clutch getting tight when it is warm & rotating freely when cold ? If not the clutch may not be working well either

[CudaHead]

I'm going to get the correct clutch from Tony's also, just in case. After all, the radiator and the fan on my car was not correct so I don't trust the clutch.

[Shane Kelley]

I don't have AC but my motor is pretty modified in both cars. I have a Glen Ray 3 row rad and clutch fan and manual trans in my Cuda and running a Milodon water pump. I run a  Flowcooler in my Road Runner and it has a replacement 4 row rad and auto trans.  Neither ever see half on the gauge. Even sitting in traffic on 90+ degree days. Both have 160 degree high flow thermostats.

[CudaHead]

And that's the way it should work. I have a 318 with a/c and it never gets close to overheating.

I ordered the correct 7 blade fan and clutch this morning from Tony's.

I'm trying to get the guy at Glen-Ray to have them build me a max-cool correct radiator but he is on vacation in Hawaii. That might take a while.
In the mean time, I also ordered a carburetor heat isolator to make sure the fuel does not boil when it heat soaks. It did when I stopped.
I also found the radiator cap was junk. I put a correct one on I got from Classic Industries.

If I still have problems, I will change the water pump and put air flow seals on the hood.

I will fix this.   

[CudaHead]

Ok, it looks like I can not get Glen-Ray to build me a radiator until Bob gets back from Hawaii in about two weeks. Then they will take the order and build it.
OK...I'm not that patient.

Can anyone suggest a backup place to get a radiator close to original?

[Burdar]

Is there a radiator shop near you?  You could have them clean and inspect your existing rad.  They might "rod it out"...clean out the tubes.  Sometimes they don't want to do that with an old rad. 

That might get you by for awhile...until you can get a new one built.

[CudaHead]

Not a bad ideal. I may go that way to buy me time.

Right now I have a lead on a  2998974 that I'm calling.

[Strawdawg]

Is the clutch getting tight when it is warm & rotating freely when cold ? If not the clutch may not be working well either

Before I started buying parts in hope of fixing it, I would check the clutch as suggested and I would also verify that car is as hot as the gauge suggests. Old factory gauges may, or may not, read correctly

[Shane Kelley]

Depending on your funds.  Put one of these in there for now. I think they run about 300ish.  4 row direct bolt in. Shroud bolts right up also.

[CudaHead]

Thanks for the reply. You did not mention where you get those.