An absolutely fantastic version of Stevie Ray Vaughan playing "Flood Down in Texas" is on the "Blues Explosion" album (blues recorded at the 1982 Montreax Jazz Festival). 10+ minutes of SRV jamming at his best.
Also, if you want some fabulous electric blues try Walter Trout "Live Trout", recorded live at the Tamps Bay Blues Festival in 2000. The CD is end-to-end electric blues.