Is is better to have a high flow water pump then the stock?Cast or aluminum? Does the thermostat need to be changed from a new 160 regular to a high volumne too?
By the end of the week the rebuilt 400 motor will also have a new radiator and fan clutch.

Someone on here recommended the stock water pump with cast impellors over the flow kooler. I went with the stock Cardone water pump, new diverter plates massaged to about .1", and a high flow 160 thermostat. I had the car out last night and she pretty much stayed at 170 and after two really long lights she got to 180. I stopped for gas and when I got back in she was at about 200, but as soon as I started her up, the temps came back down. This was in a decent amount of traffic too. Lots of stop signs, speed bumps and stop lights. For the record, I have a 4 core (non aluminum) radiator, shroud, and flex fan, but don't yet have the lower or upper filler panels. Running probably about a 30-40% antifreeze with Distilled water. It's pretty warm here so I skipped out on the full 50/50 antifreeze. Oh and a bottle of that red crap for shiz and giggles.

Will see how well the flow kooler works here when its 116 ambient temprature outside.
Time for someone to build a water pump dyno and see if its all B.S. between all these pumps.

If you want to make your head explode.

http://forums.performanceyears.com/forums/showthread.php?t=698309

For clarification, not your cars head, but your own.

I had actually ordered the flow cooler from Ames, but it was on back order so I went with the cardone since it was only ~$20. Not the biggest investment and I ended up saving about $100. Enough for upper filler panels.

Funny how many impeller shapes are out there for these pumps. I'll post a picture tomorrow of the pump I put on a GTO.

We went with the Cardone, 3 in. aluminum radiator, 160 standard thermostat, new clutch fan and extension and she ran no more then 165. Finally, i can drive the beast!!!! ..waited 4 months for this..:-)

No kidding. And Cardone is not the only company offering these pumps with cast impellers. I very recently ordered one from mine (12 years of sitting idle made for a very RUSTY crusty looking stamped steel impeller)

My new replacement definitely has a CAST impeller. It's a Gates 43102. $33.20 including free shipping to my door from Amazon.com.

The Gates impeller and pump are visually identical to this NAPA offering, which has the same part number but claims to be a "Tru Flow" brand (but is mfd by Gates). Even the casting number on my Gates is the same as shown in the Napa photos:
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=TFW43102_0363656192

Costs a little more at NAPA, but they provide lifetime warranty. I went cheap and Amazon'd it...so God only knows if I have a warranty...

Just for clarification, my 400 is a 1968, but has a motor from a 1970 Firebird 400, therefore mine takes the 11 bolt water pump instead of the 8 bolt like the 67/68 400's came with. And I think that's an important distinction many here fail to realize...that a 67/68 pump is a very unique 8 bolt animal, and they redesigned them to flow better in the later years and stuck with the new design all the way into the early 80's...

Let's add further confusion. The A-1 Cardone 11 bolt designed for the 69 and later 400's, appears to come with a stamped steel impeller...NOT cast. I find this much less desirable:
http://www.cardone.com/Products/Product-Detail?productId=58-303&make=Pontiac&model=Firebird&year=1970&info=5.7%2c+6.6+Liters+and+Standard+Pump+and+w%2fCast+Iron+Housing%3a%3a%3a

Their offering for the 67/68 8-bolt design is indeed a cast impeller....

Roxy, you have a 1969? Tells me your new Cardone came with a stamped impeller? Or no? Curious of the exact part number you purchased...

Here is a picture of an 8 bolt pump on the left and the one i took off the engine. the part number on the box also. The car gets up to 220 but thats it. All in 109 AZ heat, who really knows how acurate the temp gauge is but it never gets above 220.

See photos of the "FloKooler" vs. stock waterpump. The flow kooler didn't offer any advantages over the stock pump, in my application. Also, the casting of the flowkooler is thicker, so you'll have to do some grinding to get the alternator bracket to fit properly(no big deal, really)

@CrazeCar- My 69 400 has a 70 400 and an 11 bolt water pump. The old one that we pulled off had cast housing that was like the brand from Napa's Tru Flow. I changed it up and went with the stamped steel housing from Cardone. I know that the "Routy" video recommended the cast housing so I'm guessing he bought the High Flow FlowKooler and I stuck with the standard water flow. We have been driving the car around and the hottest its gotten with 4 grown ups in the car driving up and down hills was 180 on a 90 degree afternoon...with no schroud. Unfortunately the schroud we purchased is going back and I need one that fits the Be Cool radiator. Any tips?

The faster you move the water the less time it has to absorb or dissipate heat. The Engineer's calculated the best flow for efficiency. Leave it alone :-)