Robbor,
The biggest, longest, heaviest worm made is the 16" Snake poured by DeLong Worms. This is a throw back bait to the beginning days of stitchin' at San Diego lakes. It is a straight tail, and can be fished with a 1/16 or smaller weight because the worm itself is so heavy. We have them here at Bass World West, and most of them go to anglers heading to El Salto, but I know several guys who fish them locally and do well. Especially during the pre-spawn, that's a good idea to be looking for those big worms now. Chris.