[Nicks67GTO]

Is there a difference in cooling ability? I have a 67 GTO and it came stock with a downflow but ive read crossflows are much more efficient. Is there any reason i shouldnt run a good aftermarket aluminum downflow? {alumitech or rodney red or PY}??

[screamingchief]

This is one of those pro-con sorta discussions that could go on for ever.

Ask me,I prefer the crossflows.

The main reason is in most cases (like 95%) the crossflow radiator puts the radiator cap on the low pressure/cool/suction side of the system.

That is the more ideal location for the cap than most downflows set-ups use,most downflows have the radiator cap on the high-pressure/hot side of the system.

That typically means there is less of a chance of losing coolant with the crossflow rad.

This is mostly due to the pressure drop as coolant moves thru the core.

As a result the crossflow radiator can typically get away with using a lower cap pressure rating.

That tends to be a bit easier on all the hoses & gaskets.

It's also much better to have the cap on the suction side if one chooses to employ a coolant recovery set-up as well.

There are some pretty good reasons the OEM's no longer use the downflow rads in these sorta applications.

But I digress.

Bret P.

[Lee]

If you have a stock motor, then the stock radiator should be fine.

But if you've increased the power production, you need to increase the cooling capacity appropriately.

My current project had a downflow radiator, and it worked great for the stock motor. But, the new motor has roughly 3x the hp of the original. I tried the stock radiator, and it just could not keep up.

C&R racing built me a crossflow 2-pass, with a 3000cfm SPAL fan mounted in a custom low-profile sealed shroud. It is a rather small radiator, but has no problem keeping nearly 600hp cool.

Lee

[Nicks67GTO]

At first i was going to get an electric fan setup, but after sorting through parts i found my stock shroud and clutch fan so im going to use those. I kind of want a bolt in unit for easy of install and use of the stock shroud and fan. Rodney Red seems to have a very nice unit that is 100% bolt in and a high quality product. The only down side would be that it is a down flow unit from the looks of it and they ARE NOT cheap. The engine will probably never go beyond 550 hp at any time in this car simply because i refuse to cage it or cut anything up. I would think the rodney red unit should be fine unless somone has a better suggestion??

Will the PY unit bolt directly in and use the stock shroud and fan?