Some SBD-3 had a field mod that allowed it to carry a 58 gallon drop tank on its left wing.
SBD-5 had the inherent capacity to carry drop tanks instead of a bomb load on the wings.
Later marks of SBD-5 also carried ASB radar, operated by the gunner.
Apparently, there were a number of field mods to the SBD-5, although I haven't yet found pictures of them.
"Racks carrying multiple small bombs were fitted to the two wing bomb racks for ground attacks. Later provision for carrying a 1,600 lb. armor-piercing bomb on the center rack were qualified, though not for catapulting. [That is, this load was approved for take-off and landing on a carrier, but without catapult assisted take off] Pods carrying twin .50 guns were developed to be carried on the wing bomb racks, though infrequently used in combat. More often used were rockets mounted on underwing racks installed between the bomb racks and the radar antennas."
http://www.history.navy.mil/content/...pdfs/sbd-5.pdf
Picture of FFAR rockets mounted on SBD-5:
https://upload.wikimedia.org/wikiped...FAR_on_SBD.png