I am getting ready to purchase one of these, and I was hoping to get some opinions on which one is the best. I am leaning towards either a CSR or a Meziere. The pump is going on a Big Block. Does anybody have any experience with either of these??

They are both great pumps. Flow is equal. Just choose one ;)

Look into the MOROSO billet pump. I believe it flows more in real world conditions. I have one on my 70 SS. 10.5 compr. 470BB. Estimated around 670 HP with E heads. With stock radiator, it rarely goes near 200 degrees. I run no T-stat, and have a Moroso temp switch in one head to turn on the pump when the temp. hits 165. The electric fan is almost never turned on.

Thanks for the reply guys! I checked out the Moroso pump on Summit's website, and it looks pretty good. This might be a stupid question, but do you have to run the relay with electric pumps, or can you just have them hooked to on on/off toggle switch?

You should run a really on any high amperage electrical item in your car (lights, waterpumps, fans, ect.) This makes sure you get full voltage to the fuel pump.

Seriously consider the Meziere 55gal pump.