Oh just a note on cooling. If you are trying to lower weight AND have better cooling, an aluminum radiator may not get much more weight reduction than the stock radiator because the overall weight of the radiator is going to be governed by it's capacity and the volume of fluid. The radiator isn't going to have much to add or subtract, maybe a pound or less.
The aluminum radiator will certainly improve cooling given the same surface area as brass, so to get a weight reduction you would need to get an aluminum radiator that has the same cooling capacity as the brass stock one, but a smaller area (kind of a catch 22, I don't recomend it!).
You should also consider the coolant flow and match the stock system to prevent cavitation which will damage the engine.
If I were you, I wouldn't be concerned by weight reducion but greater cooling capacity. One area I wouldn't cut corners or pounds on.
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'89 245 Sportwagon, '04 V70 2.5T Sportwagon