I was wondering what benifits and detriment I would see putting in a big block radiator over my standard 3 core SB unit. My radiator is fairly new but I rebuilt my engine this year with more hp and although it never overheats the electric fans seem to run more even on the hwy. Would a bigger radiator eliminate this? Is it worth the extra money and trashing a perfectly good sb radiator?

The Std radiator in good with std clutch fan and shroud is way over built
On th highway, it is doubtfull the fans will be working, there is more than enough air passing thru to cool....more than the fans would ever move...if there are no restrictions..
Why fix something thats not broke?

And althu u have "more power" that doesnr mean u are using more power on the highway cruising..for hills and cruising u will be only using devaloping 20 maybe 50 hp...to maintain .

At highway speeds the fans should not be running. If the car isn't running hot I wouldn't change anything. Are your fans in a shroud? If not I would suggest getting a shroud. If you already have a shroud make sure it's sealed to the core and has enough core coverage. You want it to cover at least 90% of the radiator core.