as far as i know, they dont have any noticeably enlarged teeth and im not sure about venom. if they do it doesnt seem too powerful. you should try on the venomous forums like goini said. you can try the venommdoc forums as well, Dr. Fry states that the only truly non venomous colubrids are american pantherophis, lampropeltis, pituophis and some relatives, not sure if racers are included in the colubrine relatives he was speaking of but i do know that old world coluber have caused some potentially serious bites, or at least producing noticeable symptoms but again, their relationship to new world coluber may just be artificial.
check out the venomdoc site and you will learn alot about evolution of the venom gland and colubridae, i asked a similar question there about colubrid venom in general and Dr. Fry cleared it up nicely so give that a try along w/ the venomous forums here
hope this helped