Bob,3.9's can be found.I'll look at work again tommorrow and try to get a few places to look.Though most 3.73 and 3.91's were non-lsd.I'll also get the 2wd toyota truck info,for gear sets and post it soon. 3.07,3.42,3.58,3.73,3.91,4.10,4.30 can all be purchased as a factory gear set :multi: