Absolutely run the biggest electric fan you can behind the radiator. Electric fans are much more efficient than mechanical fans, because at idle, where you need the fan the most (traffic lights, etc.) the mechanical fan is only spinning at maybe 1000 rpms. WIth a really good (SPAL) electric fan, it will feel like a hurricane comparatively.

If you want, build an aluminum shroud around the electric fan, but I don't run one on my truck, and I live in Florida.

Don