It's generally well known that the late Stevie Ray Vaughan played with a pretty heavy set of strings on his Strat (.056 - .013), but then he tuned down to make the strings at least a bit easier to bend. Most guitarists prefer not to play such a heavy gauge set of strings. But here's a little trick that can help you sound just a tiny bit more like SRV: Leave the highest three strings at a gauge you prefer, usually .009s or .010s, then place slightly heavier gauge strings on the lowest three (.030, .042 and .052 should do it). You'll find that the chunkier low notes make your overall sound richer and fuller, while you can still easily bend the highest three strings. Ernie Ball makes a set of strings it calls "Slinky Top, Heavy Bottom" that deliver exactly the kind of tone we're talking about and GHS has a similar set.