Stock water pumps work the best for me on both of my cars. Drove both of my cars this week in the pretty high heat with no issues. My entire cooling system is mostly stock and nothing else is.

I just put a stock water pump on my 71 440 6 pak last week. It replaced the 10 year old one before it. I have driven the car over 100 miles in the last 7 days with it in pretty high heat, no issues like I said above.

I got the pump from Summit racing, they did not have it in stock. It took like 4-5 days to get to me. That says to me everyone is buying non stock pumps to try to solve other over heating issues.

Don't buy something after market and expect it to solve another problem with your setup.

Tune the car also to insure it's fuel mixture is correct. That means try the jet above what your running and below what your running now and then decide which way to go. It's fun feeling the difference and rewarding. That is one reason they can run hot, imo.

And no you wouldn't change the cap, it needs to be 15-16lbs. I am running 15# GM caps on both of my cars, 15 is not a problem verses 16#. For 4-5 years now I have been running those caps since the last of my OEMs ones wore out. Not saying it's best, it was convenient to pick out of Summit's catalog one day is why I have them.

I do not run a catch /recovery bottle in my 71, I do on my 340 lately(3years).
But did not have it when I went up pikes or Reno. Then had it in Vegas the second time I was there with the car, it made a positive difference. My temp gauge stayed more stable. I couldn't see the thermostat opening and closing on the temp gauge no more.

New water pump, I guess the aluminum water pump housing is not stock, sorry.

This is the old "Cat"(Chinese, didn't know 11-12 years ago when I bought it off E bay. Seal started leaking after a radiator flush a few weeks ago.) water pump I took out. I guess it is not stock because of the impeller? It worked fine just like the stock volume I just put back in with regular paddles on the impleller.

Here's the empty box with the brand name on it, stock volume pump that Summit did not have in stock.

Me driving the car last night in light rain sprinkles.


Oh yea, my 340 has a mildon 7 qt oil pan on it, it's wide at the bottom and closer to the ground than stock, it does not seem to contribute to over heating on my setup. I would think 7 qts is better than 5 heat wise? It was used in Vegas stop and go traffic at 110-115° temps on 2 different trips.