[Zderf]

Just a couple thoughts here.

1. Do you have an expansion tank?

If yes, is it the high point of your cooling system?

Is this where you bled the air with the radiator cap off?

Does the temperature of the coolant in the expansion tank rise as quickly as that of your temperature sender (mounted on the intake I suppose)? How about the inlet and discharge hoses on the radiator... are they that hot as quickly as your temp indicator?

Where I'm going with this is two fold. It is harder and takes longer to bleed the air out of the system than one might think, and your problem sounds like air to me. Second, I wonder if you have a blockage somewhere that is restricting flow from the water pump discharge (gasket? block?), or back to the tank and radiator.

2. I would comment on the suggested coolant mixture. Always run at least 5% antifreeze for its rust and corrosion protection, I run 10%. Use distilled or de-ionized water for the rest of the volume. I agree with Jay, Purple Ice has worked best for me.

I feel your pain. Been there, and finally found the right mix of things (expansion tank, Edelbrock high flow pump with underdrive, coolant mixture, 3 fans). Ahhh, it felt good.

Best of luck to you!!!

Zderf